Gradle Plugin for creating Processing Libraries

[Stefterv]

This PR will add a Gradle Plugin for defining Processing/Java libraries, it reduces the necessary setup of creating a new Processing library to following in a build.gradle.kts file.

  plugins{
      id("org.processing.library")
  }
  
  processing {
      library {
          version = 1
          prettyVersion = "1.0.0"
  
          authors = mapOf(
              "The Processing Foundation" to "https://processing.org"
          )
          url = "https://processing.org/"
          categories = listOf("file", "exporter", "dxf")
  
          sentence = "DXF export library for Processing"
          paragraph =
              "This library allows you to export your Processing drawings as DXF files, which can be opened in CAD applications."
  
      }
  }

This will add the functionality of bundling a Processing library as a .zip and .pdex as well as functionality to install the new library directly into Processing to test.

I think we should create similar plugins for modes and tools!

TODO

After merging

• Add Gradle Publishing logic
• Migrate integrated libraries to new plugin
• Find and test a way to connect the debugger connected to Gradle towards running sketches in Processing for easy debugging when writing libraries.
• After publishing, update the gradle library template.

@tychedelia I've put the plugin in gradle/plugins rather than buildSrc as I'd like to avoid growing the top level folders in the repo, curious what you think about that or if I should rather stick to convention? So far functionality wise it seems the same.