Move haskell-utils-* from haskell-commands.el to utils package if possible, rename otherwise

[geraldus]

There are several utility functions defined in haskell-commands.el. I think it's better to move them into haskell-utils.el if possible, and rename prefix to haskell-commands-. I think we can move those functions which does not depends on other haskell-mode functionality, for example haskell-utils-capture-expr-bounds uses haskell-spanable-pos-at-point internally and likely it is first candidate to rename rather than move.

Here is a list of this functions:

• haskell-utils-async-post-command-flag¹
• haskell-utils-capture-expr-bounds²
• haskell-utils-compose-type-at-command³
• haskell-utils-insert-type-signature⁴
• haskell-utils-echo-or-present⁵
• haskell-utils-async-update-post-command-flag⁶
• haskell-utils-async-watch-changes⁷
• haskell-utils-async-stop-watching-changes⁸
• haskell-utils-reduce-string⁹
• haskell-utils-parse-repl-response¹⁰

[gracjan]

I have removed all confusing statements. Now it is well-defined :)

[geraldus]

Nice! #752 covered all stuff, can be closed now. Good job, @ankhers !