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>

gradle/libs.versions.toml

@@ -15,6 +15,7 @@ graalVmSha256-macos-x64 = "14f4bd6417809905f86e786c779d0fc2feb840d7dac35ae3503eb
 graalVmSha256-macos-aarch64 = "e944c5ce5da56e683fc8f1a57191b46d9cb702930b1688bda064fcf467d876b8"
 graalVmSha256-linux-x64 = "112dc9b92d81a946f1b5b334646151b790785c813e76fcf13527a319003d7e2c"
 graalVmSha256-linux-aarch64 = "c95ac550d070f06666cf8c1023a098380dd565be00866473caf6ff1b7cdf680c"
+graalVmSha256-windows-x64 = "1ab2291e71f54d73e3e57b7fccbf184cabcba37e16ca9d1cf42d08474a7c02f0"
 ideaExtPlugin = "1.1"
 javaPoet = "1.+"
 javaxInject = "1"