Add Collection.values, fix editField and file return types, fix bad fields showing up in some searches

[3vorp]

Collection.values:

Getting every existing value in a collection without duplicates is a really common operation that doesn't currently exist in Firestorm at all, so I added a fully tested and typed Collection.values method. It's a slightly simpler version of the SQL SELECT DISTINCT statement, but it also supports directly merging array fields using the flatten option (useful for texture tags, user roles, etc).

Type fixes:

• Collection.editField and Collection.editFieldBulk now return confirmations like the other write methods (although different to the WriteConfirmation type used by all other write methods?)
• files.upload and files.delete extract the Axios request and return WriteConfirmations like all other methods.
• Collection.select now picks the correct return parameters directly instead of returning a partial object (this was actually painful).
• Replaced broken NoMethods<T> type with a more generalized RemoveMethods<T> type.
• Method fields are no longer shown as valid in searches and selections.
• Replaced Writable<T> with more specific Settable<T> and Addable<T> types for set and add operations respectively.

Other changes:

• Started using changelog again.
• Ran everything through a spelling checker.
• Updated type tests with the new typing system.
• Use JSDoc {@link } properties.
• Cleaned up README (again).

[TheRolfFR]

I would rather implement values on the server side