Feat: Add some API that other mods can use to dynamically hide/unhide skills

[XxX-Daniil-underscore-Zaikin-XxX]

As per this issue on nexus

To do this:

• [ ] Expose a function to read the hidden status of a given mod (either by name or by showMenu)
• [ ] Expose a function to write to this hidden status - this should also save it to file
• [ ] Use it in action by converting a mod or two to work like this (Ascension seems like a good first candidate)