fix: unify and fix tests queryGenerator.arithmeticQuery/dropTableQuery/showIndexesQuery/describeTableQuery

[WikiRik]

Pull Request Checklist

• Have you added new tests to prevent regressions?
• If a documentation update is necessary, have you opened a PR to the documentation repository?
• Did you update the typescript typings accordingly (if applicable)?
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Description Of Change

This PR unifies and fixes the following queryGenerator functions;

• arithmeticQuery
• dropTableQuery
• showIndexesQuery (added a FIXME for specifying the schema in the options, will be done in feat: add queryInterface.changeColumns, fix many bugs with changeColumn #14687)
• describeTableQuery (added a FIXME for specifying the schema in the options, will be done in feat: add queryInterface.changeColumns, fix many bugs with changeColumn #14687)

Merge Squash Commit Message Body (for breaking changes)

BREAKING CHANGE: **ibmi** - dropTableQuery does not accept schema in the options anymore, use a tableName object

[ephys]

I'm looking forward to seeing this merged. It's a good step towards cleaning up our APIs and tests!

[WikiRik]

I might probably be missing something, but I think this PR should be good to go for now.
I'll update describeTableQuery with the new extractTableDetails in a different PR.

[ephys]

Up to you if you want to improve the test or not

[WikiRik]

We'll improve it in a future refactor, for now it should be fine.