Implement Date parsing according to the spec

[raskad]

This PR implements parsing in Date() and Date.parse() according to the spec.

Until now we only parsed the given string in the RFC 3339 format. The spec allows for a more relaxed format, for example partial formats are allowed (e.g. 2024, 2024T00:00, ...). While the spec allows for implementation specifc parsing it also specifies that the output of Date.toString, Date.toUTCString and Date.toISOString must be parsable into an equal Date object. These formats are now also parsed (the Date.toISOString format is the same that the spec defines itself).

[github-actions]

Test262 conformance changes

Test result	main count	PR count	difference
Total	95,960	95,960	0
Passed	76,534	76,548	+14
Ignored	18,477	18,477	0
Failed	949	935	-14
Panics	0	0	0
Conformance	79.76%	79.77%	+0.01%

Fixed tests (14):

test/built-ins/Date/S15.9.2.1_A2.js [strict mode] (previously Failed)
test/built-ins/Date/S15.9.2.1_A2.js (previously Failed)
test/built-ins/Date/15.9.1.15-1.js [strict mode] (previously Failed)
test/built-ins/Date/15.9.1.15-1.js (previously Failed)
test/built-ins/Date/parse/without-utc-offset.js [strict mode] (previously Failed)
test/built-ins/Date/parse/without-utc-offset.js (previously Failed)
test/built-ins/Date/parse/zero.js [strict mode] (previously Failed)
test/built-ins/Date/parse/zero.js (previously Failed)
test/built-ins/Date/prototype/toUTCString/negative-year.js [strict mode] (previously Failed)
test/built-ins/Date/prototype/toUTCString/negative-year.js (previously Failed)
test/built-ins/Date/prototype/toDateString/negative-year.js [strict mode] (previously Failed)
test/built-ins/Date/prototype/toDateString/negative-year.js (previously Failed)
test/built-ins/Date/prototype/toString/negative-year.js [strict mode] (previously Failed)
test/built-ins/Date/prototype/toString/negative-year.js (previously Failed)

[codecov]

Codecov Report

Attention: 52 lines in your changes are missing coverage. Please review.

Comparison is base (35df2de) 47.42% compared to head (27c2c1c) 47.44%.
Report is 3 commits behind head on main.

Files	Patch %	Lines
core/engine/src/builtins/date/utils.rs	59.68%	52 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3564      +/-   ##
==========================================
+ Coverage   47.42%   47.44%   +0.02%     
==========================================
  Files         470      470              
  Lines       45690    45809     +119     
==========================================
+ Hits        21667    21734      +67     
- Misses      24023    24075      +52     

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[nekevss]

This looks good to me! I really like some aspects of it!

I was going to have a bit of a nit about MINUS being used, but it looks like it's not in the ECMAScript spec 😅

[nekevss]

Oooooh, I like this. Definitely makes other parts of parsing a lot nicer too!

[HalidOdat]

Nice work! Looks good to me! :)