Enable stricter Gradle plugin validation

[3flex]

Pull Request Details

Improves cacheability of plugin tasks.

Description

1. Enable stricter Gradle plugin validations
2. Remove unnecessary property annotations from extension
3. Add missing property annotations to tasks

Related Issue

Addresses one of the points raised in #1134, specifically:

The properties should be annotated correctly
https://docs.gradle.org/current/userguide/more_about_tasks.html#table:incremental_build_annotations

Closes #1258

Motivation and Context

This improves the state of Gradle incremental builds and also identifies tasks that are missing annotations that declare whether they're cacheable or not. Both of these improve build performance.

Changing the configuration of the validatePlugins task to use stricter checks will ensure this problem doesn't occur again as new tasks and properties are added.

How Has This Been Tested

Ran ./gradlew validatePlugins. I haven't done testing of the tasks though. The annotations need to be reviewed by someone who has detailed knowledge of each task before merging.

Types of changes

• Docs change / refactoring / dependency upgrade
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• 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.

[hsz]

Thank you very much for taking care of it, Matthew!

For tasks you've marked with UntrackedTask that download additional resources – I'll extract CLI tools downloading to separated tasks (as they may or may not be executed when the latest value is used as a CLI version), so the actual task will be possible to get cached if CLI is already available.