Encode filepaths to be safe on Windows

This changes the file paths to use characters that are safe for Windows.

Channges the output of the following:
* Package cache directory
* Generated pkl-doc files
* Kotlin generated code

Unsafe characters are encoded as (<hex>).
For example, the colon character `:` is encoded as `(3a)`.

Additionally, this changes the cache directory prefix (package-1 to
package-2).

Follows the design of https://github.com/apple/pkl-evolution/pull/3

pkl-doc/src/test/files/DocGeneratorTest/output/index.html

@@ -114,7 +114,7 @@ age: Int
                 <div class="member-modifiers">package </div>
               </div>
               <div class="member-main">
-                <div class="member-signature"><a class="name-decl" href="./localhost:0/birds/current/index.html">localhost:0/birds</a></div>
+                <div class="member-signature"><a class="name-decl" href="./localhost(3a)0/birds/current/index.html">localhost:0/birds</a></div>
               </div>
             </div>
           </li>
@@ -125,7 +125,7 @@ age: Int
                 <div class="member-modifiers">package </div>
               </div>
               <div class="member-main">
-                <div class="member-signature"><a class="name-decl" href="./localhost:0/fruit/current/index.html">localhost:0/fruit</a></div>
+                <div class="member-signature"><a class="name-decl" href="./localhost(3a)0/fruit/current/index.html">localhost:0/fruit</a></div>
               </div>
             </div>
           </li>

pkl-doc/src/test/files/DocGeneratorTest/output/localhost(3a)0/birds/0.5.0/Bird/index.html

@@ -4,7 +4,7 @@
     <title>Bird (localhost:0/birds:0.5.0) • Docsite Title</title>
     <script src="../../../../scripts/pkldoc.js" defer="defer"></script>
     <script src="../../../../scripts/scroll-into-view.min.js" defer="defer"></script>
-    <script src="../../../../data/localhost:0/birds/0.5.0/Bird/index.js" defer="defer"></script>
+    <script src="../../../../data/localhost(3a)0/birds/0.5.0/Bird/index.js" defer="defer"></script>
     <link href="../../../../styles/pkldoc.css" media="screen" type="text/css" rel="stylesheet">
     <link rel="icon" type="image/svg+xml" href="../../../../images/favicon.svg">
     <link rel="apple-touch-icon" sizes="180x180" href="../../../../images/apple-touch-icon.png">

pkl-doc/src/test/files/DocGeneratorTest/output/localhost(3a)0/birds/0.5.0/allFruit/index.html

@@ -4,7 +4,7 @@
     <title>allFruit (localhost:0/birds:0.5.0) • Docsite Title</title>
     <script src="../../../../scripts/pkldoc.js" defer="defer"></script>
     <script src="../../../../scripts/scroll-into-view.min.js" defer="defer"></script>
-    <script src="../../../../data/localhost:0/birds/0.5.0/allFruit/index.js" defer="defer"></script>
+    <script src="../../../../data/localhost(3a)0/birds/0.5.0/allFruit/index.js" defer="defer"></script>
     <link href="../../../../styles/pkldoc.css" media="screen" type="text/css" rel="stylesheet">
     <link rel="icon" type="image/svg+xml" href="../../../../images/favicon.svg">
     <link rel="apple-touch-icon" sizes="180x180" href="../../../../images/apple-touch-icon.png">

pkl-doc/src/test/files/DocGeneratorTest/output/localhost(3a)0/birds/0.5.0/catalog/index.html

@@ -4,7 +4,7 @@
     <title>catalog (localhost:0/birds:0.5.0) • Docsite Title</title>
     <script src="../../../../scripts/pkldoc.js" defer="defer"></script>
     <script src="../../../../scripts/scroll-into-view.min.js" defer="defer"></script>
-    <script src="../../../../data/localhost:0/birds/0.5.0/catalog/index.js" defer="defer"></script>
+    <script src="../../../../data/localhost(3a)0/birds/0.5.0/catalog/index.js" defer="defer"></script>
     <link href="../../../../styles/pkldoc.css" media="screen" type="text/css" rel="stylesheet">
     <link rel="icon" type="image/svg+xml" href="../../../../images/favicon.svg">
     <link rel="apple-touch-icon" sizes="180x180" href="../../../../images/apple-touch-icon.png">

pkl-doc/src/test/files/DocGeneratorTest/output/localhost(3a)0/birds/0.5.0/index.html

@@ -4,7 +4,7 @@
     <title>localhost:0/birds (0.5.0) • Docsite Title</title>
     <script src="../../../scripts/pkldoc.js" defer="defer"></script>
     <script src="../../../scripts/scroll-into-view.min.js" defer="defer"></script>
-    <script src="../../../data/localhost:0/birds/0.5.0/index.js" defer="defer"></script>
+    <script src="../../../data/localhost(3a)0/birds/0.5.0/index.js" defer="defer"></script>
     <link href="../../../styles/pkldoc.css" media="screen" type="text/css" rel="stylesheet">
     <link rel="icon" type="image/svg+xml" href="../../../images/favicon.svg">
     <link rel="apple-touch-icon" sizes="180x180" href="../../../images/apple-touch-icon.png">

pkl-doc/src/test/files/DocGeneratorTest/output/localhost(3a)0/fruit/1.1.0/Fruit/index.html

@@ -4,7 +4,7 @@
     <title>Fruit (localhost:0/fruit:1.1.0) • Docsite Title</title>
     <script src="../../../../scripts/pkldoc.js" defer="defer"></script>
     <script src="../../../../scripts/scroll-into-view.min.js" defer="defer"></script>
-    <script src="../../../../data/localhost:0/fruit/1.1.0/Fruit/index.js" defer="defer"></script>
+    <script src="../../../../data/localhost(3a)0/fruit/1.1.0/Fruit/index.js" defer="defer"></script>
     <link href="../../../../styles/pkldoc.css" media="screen" type="text/css" rel="stylesheet">
     <link rel="icon" type="image/svg+xml" href="../../../../images/favicon.svg">
     <link rel="apple-touch-icon" sizes="180x180" href="../../../../images/apple-touch-icon.png">

pkl-doc/src/test/files/DocGeneratorTest/output/localhost(3a)0/fruit/1.1.0/index.html

@@ -4,7 +4,7 @@
     <title>localhost:0/fruit (1.1.0) • Docsite Title</title>
     <script src="../../../scripts/pkldoc.js" defer="defer"></script>
     <script src="../../../scripts/scroll-into-view.min.js" defer="defer"></script>
-    <script src="../../../data/localhost:0/fruit/1.1.0/index.js" defer="defer"></script>
+    <script src="../../../data/localhost(3a)0/fruit/1.1.0/index.js" defer="defer"></script>
     <link href="../../../styles/pkldoc.css" media="screen" type="text/css" rel="stylesheet">
     <link rel="icon" type="image/svg+xml" href="../../../images/favicon.svg">
     <link rel="apple-touch-icon" sizes="180x180" href="../../../images/apple-touch-icon.png">