Implement String.prototype.isWellFormed and String.prototype.toWellFormed

[raskad]

This Pull Request changes the following:

• Implement String.prototype.isWellFormed and String.prototype.toWellFormed

[github-actions]

Test262 conformance changes

Test result	main count	PR count	difference
Total	95,260	95,260	0
Passed	74,952	74,984	+32
Ignored	19,230	19,198	-32
Failed	1,078	1,078	0
Panics	0	0	0
Conformance	78.68%	78.72%	+0.03%

Fixed tests (32):

test/built-ins/String/prototype/toWellFormed/not-a-constructor.js [strict mode] (previously Ignored)
test/built-ins/String/prototype/toWellFormed/not-a-constructor.js (previously Ignored)
test/built-ins/String/prototype/toWellFormed/return-abrupt-from-this.js [strict mode] (previously Ignored)
test/built-ins/String/prototype/toWellFormed/return-abrupt-from-this.js (previously Ignored)
test/built-ins/String/prototype/toWellFormed/length.js [strict mode] (previously Ignored)
test/built-ins/String/prototype/toWellFormed/length.js (previously Ignored)
test/built-ins/String/prototype/toWellFormed/to-string-primitive.js [strict mode] (previously Ignored)
test/built-ins/String/prototype/toWellFormed/to-string-primitive.js (previously Ignored)
test/built-ins/String/prototype/toWellFormed/to-string.js [strict mode] (previously Ignored)
test/built-ins/String/prototype/toWellFormed/to-string.js (previously Ignored)
test/built-ins/String/prototype/toWellFormed/name.js [strict mode] (previously Ignored)
test/built-ins/String/prototype/toWellFormed/name.js (previously Ignored)
test/built-ins/String/prototype/toWellFormed/prop-desc.js [strict mode] (previously Ignored)
test/built-ins/String/prototype/toWellFormed/prop-desc.js (previously Ignored)
test/built-ins/String/prototype/toWellFormed/returns-well-formed-string.js [strict mode] (previously Ignored)
test/built-ins/String/prototype/toWellFormed/returns-well-formed-string.js (previously Ignored)
test/built-ins/String/prototype/isWellFormed/not-a-constructor.js [strict mode] (previously Ignored)
test/built-ins/String/prototype/isWellFormed/not-a-constructor.js (previously Ignored)
test/built-ins/String/prototype/isWellFormed/return-abrupt-from-this.js [strict mode] (previously Ignored)
test/built-ins/String/prototype/isWellFormed/return-abrupt-from-this.js (previously Ignored)
test/built-ins/String/prototype/isWellFormed/length.js [strict mode] (previously Ignored)
test/built-ins/String/prototype/isWellFormed/length.js (previously Ignored)
test/built-ins/String/prototype/isWellFormed/to-string-primitive.js [strict mode] (previously Ignored)
test/built-ins/String/prototype/isWellFormed/to-string-primitive.js (previously Ignored)
test/built-ins/String/prototype/isWellFormed/returns-boolean.js [strict mode] (previously Ignored)
test/built-ins/String/prototype/isWellFormed/returns-boolean.js (previously Ignored)
test/built-ins/String/prototype/isWellFormed/to-string.js [strict mode] (previously Ignored)
test/built-ins/String/prototype/isWellFormed/to-string.js (previously Ignored)
test/built-ins/String/prototype/isWellFormed/name.js [strict mode] (previously Ignored)
test/built-ins/String/prototype/isWellFormed/name.js (previously Ignored)
test/built-ins/String/prototype/isWellFormed/prop-desc.js [strict mode] (previously Ignored)
test/built-ins/String/prototype/isWellFormed/prop-desc.js (previously Ignored)

[codecov]

Codecov Report

Merging #3187 (5e471ad) into main (2b01ef1) will decrease coverage by 0.02%.
The diff coverage is 11.76%.

@@            Coverage Diff             @@
##             main    #3187      +/-   ##
==========================================
- Coverage   50.41%   50.39%   -0.02%     
==========================================
  Files         436      436              
  Lines       42343    42360      +17     
==========================================
+ Hits        21346    21348       +2     
- Misses      20997    21012      +15     

Files Changed	Coverage Δ
boa_engine/src/builtins/string/mod.rs	56.02% <11.76%> (-0.94%)	⬇️

[HalidOdat]

Looks good to me! :)

[nekevss]

LGTM