Capitalisation: Add camelCase

[WittierDinosaur]

Brief summary of the change made

This PR adds camelCase to the extended capiltalisation policy. Added tests to cover its functionality.
Fixes #5768

Are there any other side effects of this change that we should be aware of?

I made it so the complex types are all only available when explicitly set in the config.
All 3 are either destructive to the code, or could allow poorly linted files through. Most people would use upper or lower anyway, so requiring the complex cases to be explicit should be a non-issue.

This will require a minor version bump.

Pull Request checklist

• Please confirm you have completed any of the necessary steps below.

• Included test cases to demonstrate any code changes, which may be one or more of the following:

  • .yml rule test cases in test/fixtures/rules/std_rule_cases.
  • .sql/.yml parser test cases in test/fixtures/dialects (note YML files can be auto generated with tox -e generate-fixture-yml).
  • Full autofix test cases in test/fixtures/linter/autofix.
  • Other.

• Added appropriate documentation for the change.

• Created GitHub issues for any relevant followup/future enhancements if appropriate.

[github-actions]

Coverage Results ✅

Name    Stmts   Miss  Cover   Missing
-------------------------------------
TOTAL   17798      0   100%

225 files skipped due to complete coverage.

[coveralls]

coverage: 99.985%. remained the same
when pulling eb32509 on feat-camelCase
into 9f1446f on main.

[alanmcruickshank]

Can you elaborate in the docs? I think the logic makes sense but I'm having trouble checking that it's consistent without it clearly documenting what it's supposed to do.

[alanmcruickshank]

I think the precedence rules here aren't very easy to guess. I think from running through the examples below, that I understand the logic - but I think we should document it here.

If nothing else - someone will ask on the slack channel and I'd like to be able to point them to something to explain why the default config is acting the way that it is.

[nstringham]

Any update on this?

[atishay]

How can we help getting this merged?

[alanmcruickshank]

LGTM. I agree there's some strange inference on fixing camel case situations, but I don't have any better ideas!