Add 'Copy path' button to file view (#32584)

Also adds a tooltip which is replicated to the same button in the diff
box. Fixes: https://github.com/go-gitea/gitea/issues/32583

options/locale/locale_en-US.ini

@@ -104,6 +104,7 @@ copy_url = Copy URL
 copy_hash = Copy hash
 copy_content = Copy content
 copy_branch = Copy branch name
+copy_path = Copy path
 copy_success = Copied!
 copy_error = Copy failed
 copy_type_unsupported = This file type cannot be copied