Add the `--name` option to `rad patch checkout`. This allows the user
to name the branch they are checking out, rather than use the
`patch/<short-id>` format.
This change includes returning early for setting the upstream branch,
if the upstream already existed.
Signed-off-by: Fintan Halpenny <fintan.halpenny@gmail.com>
X-Clacks-Overhead: GNU Terry Pratchett