These didn't really need to use `jj checkout`, and it will be deprecated in a
future change anyway. Move them out of there and into `new`.
Ideally this would go into `test_conflicts.rs`, but that exists in `jj-lib`, so
it doesn't have `TestEnvironment` available to it.
Signed-off-by: Austin Seipp <aseipp@pobox.com>
Change-Id: If0173b27ab4d1f6036a4ec632ec77b6824f310c3
Repeating these is a no-op. This allows:
```shell
jj new -r a -r b # Equivalent to jj new a b
jj new --before a --before b # Equivalent to jj new a b --before
```
I keep typing the latter and getting an annoying error.
They are shown next to the change and commit id, since they are other names the
commit can be referred by.
The description is separated from the branches by a ` | ` when there are
branches, so that one can tell the branches from the description without color.
The result looks like this: ![image](https://github.com/martinvonz/jj/assets/4123047/a38aff7b-2b47-49e6-8461-c42e8eb535a4)