repl: Set up a way to copy output from the REPL (#16649)

Closes #15494

Simple copy button to copy an individual output since selection is a bit
more work.

<img width="790" alt="image"
src="https://github.com/user-attachments/assets/4a7d8b69-70cc-428e-8fe3-b95386d341ee">


Release Notes:

- repl: Copy output from the REPL using a button

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Co-authored-by: Mikayla <mikayla@zed.dev>