Add `"declaration"` scope type

[wenkokke]

Add a scope type for top-level declarations, e.g., functions, classes, types, interfaces, etc.

[wenkokke]

Here's all the top-level declarations for Haskell, together with the scope types that (might) fit them:

• adt declaration ("type")
• class declaration ("class")
• data family declaration ("type"? "funk"?)
• data instance declaration ("type"? "funk"?)
• default declaration (-)
• deriving declaration (-)
• fixity declaration (-)
• foreign export declaration ("funk"?)
• foreign import declaration ("funk"?)
• function declaration ("funk")
• import declaration (-)
• instance declaration ("class"?)
• newtype declaration ("type")
• pattern synonym declaration (-)
• role annotation declaration (-)
• type alias declaration ("type")
• type family declaration ("type"? "funk"?)
• type instance declaration ("type"? "funk"?)

It'd be great to capture all these as "declaration" rather than not targeting them or adding separate scope types for each.

[pokey]

I'm guessing this is a swear word in the Haskell world, but we would call those "state" in other languages. Considering talon commands and scm patterns are also called "state", I don't think this is more of an abuse than those