VM rename test and fix

[justinc1]

Integration test is added to show that renaming VM a second time (idempotence test) does fail in current main. Problem is (in most places) we search for VM by vm_name only, but we should by vm_name xor vm_name_new. A helper function VM.get_by_old_or_new_name does this, and is used in VM module.

PR was draft:

• (partially done) unit tests need to be updated
• done - sanity tests
• todo - run all integration tests
• vm_nic, vm_disk, vm_params modules should also be updated.
  • I update vm_params module only, because only vm_params and vm modules have vm_name_new param
• maybe we can do extra cleanup, and stop using old VM.get_by_name - I'm not sure, need to check all affected modules.
  • I didn't even try this - unit test update would be painful

But there is enough code for first review and comments

[justinc1]

Unit test problems with TestManageVMDisks - I didn't check why I have problems with TestManageVMNics, but not with TestManageVMDisks. At first look, those two tests are not that much different.

[justinc1]

One more note, there is problem in VM.str() implementation. It will push branch problem-with-power-state-mapping, to show this. It seems to me that we store in VM.power_state both VM power_state as retrieved from HyperCore, and sometimes also power_state as set in ansible module. But ansible power_state is actually a command describing transition to HyperCore power_state, not HyperCore power_state (e.g. you can get into SHUTOFF state by nice shutdown or by force shutdown - two different actions, same end state).

I noticed this only because I added debug module.warn. Module was not misbehaving.

It would be a bit of extra work and testing, so I just added a small workaround to not throw this error to module users.