WYSIWYG Code Editor Updates

[ssddanbrown]

Set of improvements to the code editor.

TODO

• Finish up design changes
• Made language list interact to language input, highlight and scroll list based on prefix match.
• Align language list with required changes in other issues (New additions and missing options).
• Align popup design changes across similar popups (Image manager, entity selector popup, Editor change confirmation)
• Update for dark mode compatibility
• Update for mobile compatibility

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Related to #3511 and #3494, Attempted GraphQL usage but could not use the official language without doubling bundle size.