feat: FileExplorer 'Copy path' / 'Copy relative path' context menu

[nullxnothing]

Right-click on a file in FileExplorer should have 'Copy path' and 'Copy relative path' options. Relative = from project root.

Files: src/panels/FileExplorer/

[Synergy738]

Hi I'm a new contributer and would like to fix this issue. Let me know if it's okay to proceed.