Set the column-limit in fourmolu config

[Lucsanszky]

Description

In addition to applying the formatting changes enforced by the added column-limit rule, this PR will also:

• Remove the idempotence check when running fourmolize.sh as that doesn't play well with column-limit.
  See: https://fourmolu.github.io/config/column-limit/
• Add .git-blame-ignore-revs file so we can keep track of commits with large formatting changes and ignore them when blaming.
• Make it possible to run fourmolize.sh on changed files only by supplying the --changes flag.
• Run the fourmolu GitHub action on changed files only (compared to origin/master).
• Setup pre-commit in a non-intrusive way.

For now, I disabled running the pre-commit-check as a Hydra job until we decide whether to keep the current setup (running fourmolize.sh as a GitHub action) or switch to pre-commit. Both options have their advantages, however if at one point we decide to adopt iogx, I would advocate for pre-commit via Hydra. Regardless, pre-commit will be available from now on as a git hook and one can opt-in to use it conveniently, albeit in a bit hacky way (see the SKIP flag trick detailed in CONTRIBUTING.md).

Resolves #4069

Checklist

• Commit sequence broadly makes sense and commits have useful messages
• New tests are added if needed and existing tests are updated
• When applicable, versions are updated in .cabal and CHANGELOG.md files according to the
  versioning process.
• The version bounds in .cabal files for all affected packages are updated. If you change the bounds in a cabal file, that package itself must have a version increase. (See RELEASING.md)
• All visible changes are prepended to the latest section of a CHANGELOG.md for the affected packages. New section is never added with the code changes. (See RELEASING.md)
• Code is formatted with fourmolu (use scripts/fourmolize.sh)
• Cabal files are formatted (use scripts/cabal-format.sh)
• hie.yaml has been updated (use scripts/gen-hie.sh)
• Self-reviewed the diff

[Lucsanszky]

Well... There certainly are some interesting formatting changes but I think they are more or less fine. Except for one instance that I pointed out in the code, that one really is an eyesore.

[teodanciu]

Looks good to me, very generous explanations!
I'm personally not going to use the pre-commit hook but I will certainly use the --changes flag with fourmolu, it will be great to not have to wait so long for the script.