Project Rewrite and bug fixing

[theShadowsDust]

Overview

Rewrite the project in Java and fix some small bugs.

Fixes

• Fix the cooldown time.
• Fix that players are still vanished after demoting or setting the parent group.
• Fix the tab completion for the frog variants.

### Submitter Checklist
- [X] Make sure you are opening from a topic branch (**/feature/fix/docs/ branch** (right side)) and not your main branch.
- [X] Ensure that the pull request title represents the desired changelog entry.
- [X] New public fields and methods are annotated with `@since TODO`.
- [X] I read and followed the [contribution guidelines](https://github.com/OneLiteFeatherNET/.github/blob/main/CONTRIBUTING.md).