Update create_date_time_format

[Vellumic]

This Pull Request is a preparation work before updating the logic according to Temporal proposal.

It changes the following:

• Change function signature
• Update spec comments
• Refactor IntlOptions construction
• Clean up code in some places
• Add an extra validation in step 28

[github-actions]

Test262 conformance changes

Test result	main count	PR count	difference
Total	53,578	53,578	0
Passed	51,439	51,436	-3
Ignored	1,648	1,648	0
Failed	491	494	+3
Panics	0	0	0
Conformance	96.01%	96.00%	-0.01%

Fixed tests (1):

test/intl402/DateTimeFormat/prototype/resolvedOptions/calendar.js (previously Failed)

Broken tests (4):

test/intl402/DateTimeFormat/constructor-options-calendar-future-fallback.js (previously Passed)
test/intl402/DateTimeFormat/constructor-options-order.js (previously Passed)
test/intl402/DateTimeFormat/constructor-calendar-numberingSystem-order.js (previously Passed)
test/intl402/DateTimeFormat/prototype/resolvedOptions/resolved-calendar-unicode-extensions-and-options.js (previously Passed)

Tested main commit: 39cd11214ecb366200157dab96b3919e61e9a391
Tested PR commit: b365a2c949fbe54cd10cbf78b6d1594cac023a29
Compare commits: 39cd112...b365a2c