Provide GHC-like line snippets in messages

Fixes #87 (closed)

This merge request builds on top of !26 (merged), depends on curry-base!17 (merged) and implements GHC-like line previews in error/warning messages.

Example:

data Test a = Test

demo = case 4 of
    _ -> 3
    _ -> 5

Output:

[2 of 2] Compiling TestThis         ( src/TestThis.curry, src/.curry/TestThis.fcy )

src/TestThis.curry:1:11 Warning:
    Unreferenced type variable `a'
   | 
 1 | data Test a = Test
   |           ^

src/TestThis.curry:3:1-3:4 Warning:
    Top-level binding with no type signature:
      demo :: Prelude.Num a => a
   | 
 3 | demo = case 7 of
   | ^^^^

src/TestThis.curry:5:5-5:10 Warning:
    Pattern matches are potentially unreachable
    In a case alternative:
      _ -> ...
   | 
 5 |     _ -> 5
   |     ^^^^^^