override/deduplicate installed extension when installing local clone

[friday]

Description

When installing extensions locally from a path, override/deduplicate with the installed extension url

Either need to hard code the url into the manifest as discussed in #1319 or we could get the remote url from the path with
git remote get-url origin

Communication guidelines

• I have read and agree with Ulauncher's communication guidelines and checked the existing enhancement requests before suggesting this.

Ulauncher v6

• I have checked and couldn't find my suggestion in v6.