817: Add configurability to range question type

[lindsay-stevens]

Closes #817

• initial implementation of checks
• tidy up error messages
• add tests for validations
• add tests for output
• remove or update older range tests
• check for interactions/regressions/etc e.g. with settings etc

Why is this the best possible solution? Were any other approaches considered?

Follows the specification in the linked ticket, related spec ticket, and forum post.

I was not completely clear on the discussion around asc/desc range support but there is a test test_range_spec_patterns__ok to show these variants that pass without error, even though half of them would potentially produce an empty range.

What are the regression risks?

The parameters are validated more closely now so that could cause an error where there was none before, but the added errors are intended to be consistent with what Collect and/or Webforms support anyway.

Does this change require updates to documentation? If so, please file an issue here and include the link below.

Yes, though there are already filed: getodk/docs#2031 getodk/xforms-spec#336

Before submitting this PR, please make sure you have:

• included test cases for core behavior and edge cases in tests
• run python -m unittest and verified all tests pass
• run ruff format pyxform tests and ruff check pyxform tests to lint code
• verified that any code or assets from external sources are properly credited in comments

[lognaturel]

Apologies for the messy force pushes. I keep running only one of the two classes in test_range locally and then discovering issues in the other suite! I think this accounts for everything I can think of.