Breaking change: Migrate from build plugin to settings plugin

[consp1racy]

• Isolated projects compatible. There's no formal test but the project enables the feature and uses its own plugin.
• Grade Doctor plugin no longer needs to be declared after Develocity plugin to contribute to build scans.
• Tests are now compatible with Windows.
• Tests are now compatible with Czech locale.
• Tests for JAVA_HOME are now enabled.

Test

Run ./gradlew doctor-plugin:check.

Migration

Move plugin declaration and configuration block from root project build.gradle file to settings.gradle file. No backwards compatibilit in this regard. The whole point is isolated projects compatibility which can't be attained using the original syntax.

[consp1racy]

• Noticed failed checks in CI, I'll test on a mac later.