remove string error messages

[3esmit]

Description

Fixes #11

Checklist

Ensure you completed all of the steps below before submitting your pull request:

• Added natspec comments?
• Ran forge snapshot?
• Ran pnpm lint?
• Ran forge test?

[0x-r4bbit]

Thank you for adding the snapshot's before/after states!

I think we should use this opportunity and also introduce tests that ensure these new errors are indeed thrown. While the tests had been ported, they didn't have tons of coverage.
Otherwise this PR would probably not make it through CI.

If you want to see how tests for errors can be written, check out all the tests here that are prefixed with test_RevertWhen_*:

https://github.com/status-im/communities-contracts/pull/2/files#diff-0c1702f33e161b30e89a441837d1623bb2d4cc9ff781ce300cda4f3e82ab4aa0R74-R84

Lastly, I think these commits need to be rebased on top of latest master because they still have a commit with the lint fixes that have already landed in master. That's probably also the reason there's a merge commit in this pull request.

Great work otherwise!

[0x-r4bbit]

Another thing I've just noticed: the added natspec comments checkbox is checked, but I don't see any added comments for that.

I don't think it's a big deal in this case, and I'd say checking that checkbox is optional, depending on context.
If we however introduce new contracts/functions, we should definitely add comments (and tests)