Custom remote branch path support -r, --remote-branch option for move command

[joseluisq]

This PR adds support for using a custom remote branch path like <origin>/<master> when wanting to switch to a specific remote branch. It makes it easier to switch between multiple remote branches apart from the current one (e.g., origin).

The -r, --remote-branch option requires the -u, --upstream to be provided together.

move -h
#      -r --remote-branch      Use a custom remote branch path like '<origin>/<master>' when wanting to switch. It requires the '-u, --upstream' option.

Examples

For switching to specific remote branches (not only on the current one), use these variants:

# Using it with `-u, --upstream`
move --upstream --remote-branch my-remote/my-branch
move -u -r my-remote/some/branch
move -ur my-remote/my-branch

# Using it with `-n, --no-apply-stash`
move -nur my-remote/my-branch
move -unr my-remote/some/branch

For switching to remote branches on the current remote only (e.g., origin), use these variants:

move --upstream my-branch
move -u my-branch