Adding ClickHandler to intercept useKey above closest nearby living entity, and display a debug click message

- Removing old mod textures, and static loading
- Dynamic loading of textures now working

Initial proof of concept changes to Fabric Minecraft example mod. Generate 1 random ChatGPT prompt, display it above all Living Entities.

Now uses split-sourceset's

* Update build script to support Gradle 9

* Another fix

* Fix

Also updates fabric loader.

The [old page](https://fabricmc.net/versions.html) is missing links to the online javadocs. It tells users to use the [new page](https://fabricmc.net/develop) instead, so we might as well provide the new one here to begin with.