feat: add tree view for the files in the current workspace

[Sparkier]

I made a file explorer since I was annoyed I could not see the other files in workspace. Don't know if this is something you want to add, though.

https://github.com/OpenDevin/OpenDevin/assets/5690524/42112426-cc3b-4b13-bdfc-702cb53f5daa

[Sparkier]

If this is something you want I can clean up the linter errors.

[andrescevp]

I would add a button to actually open de folder or the file with the system explorer and clean lint errors, this should be in the interface. Agree.

[rbren]

This is working great! Thank you

[foragerr]

nice! 🔥