Internalize util functionality

[aSemy]

Pull Request Details

Just a quick PR to demo #1146. There are questions about whether a deprecation cycle is needed?

I added https://github.com/Kotlin/binary-compatibility-validator. The change in the API footprint is shown in this commit

https://github.com/JetBrains/gradle-intellij-plugin/pull/1147/commits/8ac3b1adb4202dc93dbd9f66e124b09592056a65

Before is master branch, after is this PR.

Description

Related Issue

#1146

Motivation and Context

This means that when gradle-intellij-plugin is applied, these functions are made available in the build script. If gradle-intellij-plugin is imported in buildSrc/build.gradle.kts, then the util functions are available in all build scripts, even if gradle-intellij-plugin isn't applied.

This has some drawbacks

• In projects that use gradle-intellij-plugin, IntelliJ must to do more work to index these functions, degrading performance (which is already pretty poor when it comes to Gradle scripts)
• Autocomplete contains irrelevant functions
• Marking them as internal would reduce the API footprint of gradle-intellij-plugin, reducing the amount of code that needs to be supported

How Has This Been Tested

Types of changes

• [x] Docs change / refactoring / dependency upgrade
• [ ] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [x] Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• [ ] I have read the CONTRIBUTING document.
• [ ] My code follows the code style of this project.
• [ ] My change requires a change to the documentation.
• [ ] I have updated the documentation accordingly.
• [ ] I have included my change in the CHANGELOG.
• [ ] I have added tests to cover my changes.
• [ ] All new and existing tests passed.