infinitepush: drop the `--create` flag to push command
The extension added a `--create` flag for creating a new bookmark on the
bundlestore. This patch changes the bahviour to create a bookmark if it does not
exists and removes the requirement of the `--create` and then drop the logic
around the `--create` flag.
Tests are changed to drop the usage of `--create` flag.
Differential Revision: https://phab.mercurial-scm.org/D2107
$ hg init
$ echo a > a
$ hg ci -Am t
adding a
$ hg mv a b
$ hg ci -Am t1
$ hg debugrename b
b renamed from a:b789fdd96dc2f3bd229c1dd8eedf0fc60e2b68e3
$ hg mv b a
$ hg ci -Am t2
$ hg debugrename a
a renamed from b:37d9b5d994eab34eda9c16b195ace52c7b129980
$ hg debugrename --rev 1 b
b renamed from a:b789fdd96dc2f3bd229c1dd8eedf0fc60e2b68e3