fix(deps): Bump React Ace to v12, fix broken syntax highlighting

[RichDom2185]

Description

Supersedes #2880.

Also did a bit of cleanup.

Our custom syntax highlighting is still broken at the moment but other syntax highlighting works. (Fixed)

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update
• Code quality improvements

How to test

Checklist

• I have tested this code
• I have updated the documentation

[coveralls]

Pull Request Test Coverage Report for Build 11561349850

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 20 unchanged lines in 3 files lost coverage.
• Overall coverage decreased (-0.1%) to 31.342%

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Files with Coverage Reduction	New Missed Lines	%
src/commons/editor/Editor.tsx	3	39.26%
src/pages/playground/Playground.tsx	3	55.42%
src/commons/editor/UseHighlighting.tsx	14	19.61%

Totals
Change from base Build 11560362906:	-0.1%
Covered Lines:	4835
Relevant Lines:	14551

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💛 - Coveralls