fix: overhaul test suite of attribute(s)ToSQL

[WikiRik]

Description of Changes

Attempt 2 on overhauling the test suite for attributesToSQL and attributeToSQL. I also did some minor improvements to the functions.

Closes #15533

TODOs

• Confirm what is desired behaviour
• Type attributeToSQL
• Type attributesToSQL

Future PRs

• Rename to attributesToSql and attributeToSql respectively
• Clean up createTableQuery unit tests
• Move usages of attributesToSQL to queryGenerator so both can become internal functions
• Throw if invalid options/column keys are used (like comment for sqlite)
• Remove weird behaviour surrounding schema's that are used in functions that call attribute(s)ToSQL (breaking change)

List of Breaking Changes

[WikiRik]

@ephys even though it's in draft; could you take a look at the test cases that we do? As mentioned in the TODOs above, there is still work to be done but I want to confirm that this is how people can use these functions before cleaning up test suites and add typings.

[WikiRik]

I'll mark it as ready for review since the bulk of the work is done. It's not ready for merging yet, since I want to know if there's any tests that have unwanted behaviour before I work on typing the functions.