Implement validator for JS syntax in CLI

[jedel1043]

Before this change, when being on REPL mode, you could type something that is invalid Javascript but contains unclosed brackets, then press enter and the REPL would happily accept your input. For example:

>> function b() [
       let a = 5;
       let b = 6;
       let c = 7;
]
Uncaught: SyntaxError: expected token '{', got '[' in function declaration at line 1, col 14 (native at core/engine/src/script.rs:95:34)

Note that it prints an error only until the bracket is closed, even if there was already a syntax error from line 1.

What this does is to make it such that the CLI gives feedback when pressing enter if the input is already invalid JS:

>> function b() [
Uncaught SyntaxError expected token '{', got '[' in function declaration at line 1, col 14

[github-actions]

Test262 conformance changes

Test result	main count	PR count	difference
Total	52,963	52,963	0
Passed	49,713	49,713	0
Ignored	2,262	2,262	0
Failed	988	988	0
Panics	0	0	0
Conformance	93.86%	93.86%	0.00%

Tested main commit: 0919e3b2c00d75fd32968903a328e7b85989d5c5
Tested PR commit: 5dc54a27183dbc27f5189ec2a881cd5b074e8469
Compare commits: 0919e3b...5dc54a2

[codecov]

Codecov Report

❌ Patch coverage is 0% with 19 lines in your changes missing coverage. Please review.
✅ Project coverage is 58.06%. Comparing base (6ddc2b4) to head (5dc54a2).
⚠️ Report is 791 commits behind head on main.

Files with missing lines	Patch %	Lines
cli/src/helper.rs	0.00%	12 Missing ⚠️
cli/src/main.rs	0.00%	3 Missing ⚠️
core/parser/src/error/mod.rs	0.00%	2 Missing ⚠️
core/parser/src/parser/mod.rs	0.00%	2 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##             main    #4911       +/-   ##
===========================================
+ Coverage   47.24%   58.06%   +10.82%     
===========================================
  Files         476      557       +81     
  Lines       46892    61096    +14204     
===========================================
+ Hits        22154    35478    +13324     
- Misses      24738    25618      +880     

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[hansl]

I like it, but would like to see #4888 go in first.

[rajat552]

Hi @jedel1043 , I noticed that PR #4888 has already been merged.
Do you think rebasing this branch on the latest main could fix the lint failure?
I'd be happy to help test the changes if needed.