infinitepush: drop the `--to` flag to push and use `-B` instead The extension added a `--to` flag to specify the bookmark to which revs should be pushed. This patch deletes that flag and instead uses the `-B` flag. After this patch, bookmark passed as `-B` is parsed and if it matches the infinitepush bookmark pattern, we consider that push as infinitepush. This is still not the best of what we can do. Later patches in the series will drop the use of `-B` flag and will instead handle things at bookmark bundle2 part. Plugging these logic to bookmark bundle2 part will also get rid of the scratchbranchparttype bundle2 part. Differential Revision: https://phab.mercurial-scm.org/D2108