Math Formula Fields (alpha) (Blender 3.0 + )

This adds a bunch of new features and bugfixes, summarized here:

• Add support for adding functions using the fn keyword.
• Add support for adding node groups using the ng keyword.
• Add support for custom implementations. For example, the function acosh() is now well-defined.
• Fix bug with names with spaces
• Fix bug with autocomplete

For more information see the docs.md file included in the add-on folder