Adds a `rename` field to the Java/Kotlin code generators that allows renaming packages and classes during codegen.
* Add `--rename` flag to CLIs
* Add `rename` property to Gradle API
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
This reverts commit 7f404fff49.
The package is derived from the module name.
Having `module com.example.Foo` in Pkl
will create Kotlin `package com.example`.
Eventually, we may want to introduce a way to map
Pkl names to package names that provides finer
controls to the code generator.
