fix: add some new test cases
These cover a couple of behaviors we were testing at Google that weren't
covered here before.
Differential Revision: https://phab.mercurial-scm.org/D6698
unshelve: store information about interactive mode in shelvedstate
This is a follow-up patch to
5162753c4c14. This makes `unshelve`
stores the information about interactive mode on conflicts.
Differential Revision: https://phab.mercurial-scm.org/D6679