Migrate buildSrc plugins to build-logic

[alexstaeding]

As mentioned in #983, this PR migrates all buildSrc plugins to a build-logic project.

Everything should be functionally identical to the way it worked previously with the following exceptions:

• The application of the publish plugin is done individually in the api and native projects. Previously, the following if-condition in the velocity publish plugin

  Velocity/buildSrc/src/main/kotlin/com/velocitypowered/script/VelocityPublishPlugin.kt

  Line 36 in 36cc2bd

  if (target.name != "velocity-proxy") {

  would lead to the api and native project to being published. I'm not sure if publishing the native project is intended, but that can be fixed easily.

• I have centralized the repository declaration in settings.gradle.kts and enabled repositoriesMode.set(RepositoriesMode.FAIL_ON_PROJECT_REPOS)

[alexstaeding]

Applied suggested fixes for typos and fixed conflicts with base (dev/3.0.0)

[astei]

Publishing the native is intentional, it was done for Krypton

[astei]

Manually rebased and merged with 24ed83d - thanks for this