Add configure options for ghc-options layout.

[philderbeast]

Picking up #37 as a fix for #34, I've removed the sorting and added options to control this, leaving the default as-is.

$ cabal run cabal-fmt -- --help
Build profile: -w ghc-9.4.4 -O1
...

Usage: cabal-fmt [--Werror | --Wno-error | --indent N | --tabular | 
                   --no-tabular | --ghc-options-flow | --ghc-options-vert | 
                   --cabal-file | (-n|--no-cabal-file) | --stdout | 
                   (-i|--inplace) | (-c|--check)] [FILE...] [--version]

  Reformat .cabal files

Available options:
  --Werror                 Treat warnings as errors
  --indent N               Indentation
  --tabular                Tabular formatting
  --ghc-options-flow       ghc-options: flow options (default)
  --ghc-options-vert       ghc-options: one option per line
  -n,--no-cabal-file       Don't parse as .cabal file
  --stdout                 Write output to stdout (default)
  -i,--inplace             Process files in-place
  -c,--check               Fail with non-zero exit code if input is not
                           formatted
  FILE...                  input files
  -h,--help                Show this help text
  --version                Show version

The two new fixture files were generated by cabal init to which I added some ghc-options and removed some of the top-level fields, not needed for testing, like author and maintainer.

I see that cabal init generates a .cabal file with 4 spaces indentation whereas the default for cabal-fmt is 2 spaces.

[philderbeast]

If you know of a way to keep +RTS -A32M -RTS as one line while options prefixed with -W as one per line then that could be very nice.