[applevz] Unsupported ops

[sharder996]

This PR adds some polishing touches to the applevz backend in Multipass. Specifically:

• multipass snapshot throws NotImplementedOnThisBackendException
• multipass suspend foo throws NotImplementedOnThisBackendException
• VMs are returned to their original state before daemon shutdown
• AppleVZ will report a VM running as soon as the kernel has booted. Let wait_until_ssh_up to transition state to Running

---

MULTI-2256
MULTI-2269

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 87.66%. Comparing base (8d585d4) to head (4917584).
⚠️ Report is 6 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #4766   +/-   ##
=======================================
  Coverage   87.66%   87.66%           
=======================================
  Files         257      257           
  Lines       14127    14127           
=======================================
  Hits        12383    12383           
  Misses       1744     1744           

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