Add Folia basic support;

[HarvelsX]

Adds adapters for schedulers. Required for Bukkit and Folia schedulers.
Created schedulers can be used in WorldGuard and in other plugins;

• Tested in detail

[octylFractal]

I'm unsure this covers all the changes we'd need to be properly folia-supportive, but one thing for sure is I don't think we want to expose SchedulerAdapter + these Entity methods as full API. I think those belong specifically in the Bukkit section. I'm not sure we'd even like to have them be public there, but that's a discussion I'd need to have with the rest of the dev team.

[Yomamaeatstoes]

When testing whether this project would build in Ubuntu I did encounter a build failure. I pasted it in mclogs
https://mclo.gs/PXagKd8. When I tried building it in Terminal I did encounter this issue as well. I suppose they could be apart of the same issue https://mclo.gs/FGdD5KX

[octylFractal]

Yes, the new API must be accepted.