fix(plugin-export): restore plugin mode and update JSON export schema

[Meekiavelique]

Skiping datapack compilation when plugin mode is enabled, include some more settings in the json export and fixed serialization issues for text displays.

[SnaveSutit]

There is a new plugin json schema that has been planned for the next release.

https://gist.github.com/SnaveSutit/5452228de4af4b2f42e9481264c2df0c

I realize this isn't super publicly known, but it has been discussed in the plugin discussion thread in the #chat channel on our discord.

Unfortunately I won't be able to merge this PR, as it will cause a bunch of merge conflicts with the rewrite branch that I'd rather avoid.

Please follow the steps in CONTRIBUTING.md in the future. I don't want you spending your time implementing stuff that I won't be able to merge. 😢

Thank you for understanding!

[Meekiavelique]

I updated the json schema
And what do you mean by conflicts with the rewrite branch

[SnaveSutit]

The entire plugin is being rewritten from almost scratch again for Blockbench v5.0 due to major plugin API changes.

Changing / adding to the history of main will cause merge conflicts with the massively different rewrite branch

[SnaveSutit]

On top of this, it is not possible to export texture_pallets correctly, as they function differently from how Variants function currently