PYTHON-5421 Make parse_uri() return "options" as a dict rather than _CaseInsensitiveDictionary

[sleepyStick]

• Added a function _make_options_case_sensitive that takes in uri options _CaseInsensitiveDictionary and returns it in proper case sensitive plain dict form. Any keys in the original _CaseInsensitiveDictionary that aren't in the set of properly cased option names are put into the plain dict as is.
• unified tests convert options back to _CaseInsensitiveDictionary for key comparison reasons.
• parse_uri now returns "options" as a plain dict:

>>> from pymongo.uri_parser import parse_uri
>>> options = parse_uri("mongodb://localhost/?retryWrites=true&retryreads=true")["options"]
>>> options
{'retryWrites': True, 'retryReads': True}
>>> type(options)
<class 'dict'>

[aclark4life]

LGTM, thanks!

[ShaneHarvey]

Please add a changelog entry and a ..versionchanged to parse_uri to describe the breaking change. Also, do we have a test that verifies options is returned as a dict and not a custom class?

[aclark4life]

@ShaneHarvey @sleepyStick Sorry I missed that!

[sleepyStick]

Please add a changelog entry and a ..versionchanged to parse_uri to describe the breaking change. Also, do we have a test that verifies options is returned as a dict and not a custom class?

Going to make a follow up PR for these changes!