feat: improve Paper/Spigot Gradle plugin templates

[Strokkur424]

Requires minecraft-dev/MinecraftDev#2574 to be merged alongside.

This PR improves the default Paper/Spigot plugin templates by changing the following things:

• Only generate Gradle scripts with the Kotlin DSL
• Give users a choice to add the run-paper and shadowjar plugins if they so desire
• Move the project version and group declaration to gradle.properties
• Add some performance enhancing properties to gradle.properties
• Remove unnecessary java version configure logic
• Add a .gitattributes file
• Bump the Gradle plugin versions used
• Always use the latest available Gradle version, ensured by running gradle wrapper --gradle-version=latest
• Optional userdev plugin inclusion toggle
• Optional toggle for Gradle version catalog (libs.versions.toml)
• Paper PluginLoader file creation toggle
• Paper PluginBootstrap file creation toggle
• Gremlin Gradle plugin for automatic runtime download