Unify `Arguments` parsing of exe:ghcide and exe:haskell-language-server

[fendor]

The cli argument parsing for exe:ghcide and exe:haskell-language-server are very similar but separate.
I think it would be better if we extracted out a common argument parser and use the same argument parser for ghcide and haskell-language-server.

This should be reasonably simple, it requires some extraction of ghcide types from Arguments so that it can be used in exe:ghcide and exe:haskell-language-server as well