tests: improve "revert template changes" test
tests: improve "revert template changes" test

There is no more significant difference between PV and HVM. VMs are HVM
by default anyway. More important for this test is difference between
Linux (with Qubes packages installed) and other OS-es. Rename tests
accordingly. The later one is still incomplete.

marmarek/qubes-core-admin,marmarek/qubes-core-admin,QubesOS/qubes-core-admin,woju/qubes-core-admin,woju/qubes-core-admin,woju/qubes-core-admin,QubesOS/qubes-core-admin,marmarek/qubes-core-admin,QubesOS/qubes-core-admin,woju/qubes-core-admin