[Feature Request] Ability to change the current default or forced collection using a chat command

[lucyawrey]

Command format would be "/penumbra collection {default|forced} <collectionName>". The purpose of this functionality is to be able to change between mod collections on the fly without opening the Penumbra UI, including use in macros. Based on the fact that mods can already be enabled or disabled through commands, this functionality seems to be within scope.

I already wrote the code for the command for my own use, but decided to wait to make a pull request until I got approval for the feature.

[Ottermandias]

Sure, make the PR, I'll look over it.

[lucyawrey]

@Ottermandias Thanks! let me know if I need to make any changes. See pull request: #143