get-app to allow local file system copy

[varun-krishnamurthy]

Issue: Feature Request

Is your feature request related to a problem? Please describe.
In a situation wherein I have the local copy of the app, I am not able to import this app into the bench env easily. Since the Even though the bench get-app primarily depends on git, it should continue to allow importing apps from local filesystem. Even the CI process will get benefited from this (since the code is already checked out by the pipeline)

Describe the solution you'd like

bench get-app allow file:// context path . When the context uri starts with file://, instead of git clone, system should copy the file from the provided location and continue the rest of the process.

Describe alternatives you've considered

Manually copy the files and run py commands that bench runs to import the app into the bench env.
Use git to re-download the files

Additional context
I think this feature was earlier available but its not working now.