[RFC]: add commands for easy switching and previewing of syntax highlighting themes in the REPL

[Snehil-Shah]

Description

This RFC proposes

• adding commands like prevTheme and nextTheme for easier switching between syntax highlighting themes
• adding a command like themeSample that prints out a syntactically highlighted sample code to demonstrate how the current theme looks like.

Related Issues

Related discussions #2341

Questions

No.

Other

No.

Checklist

• [X] I have read and understood the Code of Conduct.
• [X] Searched for existing issues and pull requests.
• [X] The issue name begins with RFC:.

[vexora-0]

hey @Snehil-Shah can you assign this to me

[Snehil-Shah]

@vexora-0 we don't assign issues, but feel free to open a PR implementing this. I suggest also discussing your plan and implementation details beforehand to avoid wasted work.