Collasping TabEntry / Collasping Container Entry

[Guardian259]

Add an implementation of some form of collapsible entry for containers and/or Tabbed Entries.

For situations where multiple repeating sets of settings exist (Example: Biome toggles for feature generation) sifting through said sets can become both time-consuming and confusing. with the ability to denote sections of tabbed entries, screens, or widgets as collapsible a door is opened which allows for vast user customization while maintaining understand-ability and ease of use.

Possible solution: Expand upon the Separator entry to allow them to act as collapsing buttons. Widgets found between Separators are categorized and collapsed into the Separator above them. This feature could be made into a boolean, where in current Separator functionality is maintained in one state, while collapsing functionality is added in the other. Some form of name or identifier would have to be added to a separators functionality in this scenario though that in and of itself has its uses.

I do not yet know of a good way of implementing the described feature to a container itself, yet i still believe said functionality would be an immensely powerful tool in our tool-belt