Add support for Windows (#492)

This adds support for Windows.
The in-language path separator is still `/`, to ensure Pkl programs are cross-platform.

Log lines are written using CRLF endings on Windows.
Modules that are combined with `--module-output-separator` uses LF endings to ensure
consistent rendering across platforms.

`jpkl` does not work on Windows as a direct executable.
However, it can work with `java -jar jpkl`.

Additional details:

* Adjust git settings for Windows
* Add native executable for pkl cli
* Add jdk17 windows Gradle check in CI
* Adjust CI test reports to be staged within Gradle rather than by shell script.
* Fix: encode more characters that are not safe Windows paths
* Skip running tests involving symbolic links on Windows (these require administrator privileges to run).
* Introduce custom implementation of `IoUtils.relativize`
* Allow Gradle to initialize ExecutableJar `Property` values
* Add Gradle flag to enable remote JVM debugging

Co-authored-by: Philip K.F. Hölzenspies <holzensp@gmail.com>

pkl-server/src/test/kotlin/org/pkl/server/BinaryEvaluatorSnippetTests.kt

@@ -58,7 +58,8 @@ class BinaryEvaluatorSnippetTestEngine : InputOutputTestEngine() {
       null
     )
 
-  private fun String.stripFilePaths() = replace(snippetsDir.toString(), "/\$snippetsDir")
+  private fun String.stripFilePaths() =
+    replace(snippetsDir.toUri().toString(), "file:///\$snippetsDir/")
 
   override fun generateOutputFor(inputFile: Path): Pair<Boolean, String> {
     val bytes = evaluator.evaluate(ModuleSource.path(inputFile), null)