test: Make TestServices.testCreateTimer destructive
test: Make TestServices.testCreateTimer destructive

Move the test into its own TestTimers class. It's difficult to set the
time back to the original value in a synchronous and predictable manner
in an offline VM, and  that whole time shifting is not really
non-destructive.

Also, the test reboots twice, which we cannot do in Fedora dist-git
gating. Moving into its own class will make it easier to run the
remaining TestServices there.

mvollmer/cockpit,deryni/cockpit,cockpituous/cockpit,mvollmer/cockpit,martinpitt/cockpit,cockpituous/cockpit,cockpituous/cockpit,mvollmer/cockpit,moraleslazaro/cockpit,martinpitt/cockpit,moraleslazaro/cockpit,deryni/cockpit,martinpitt/cockpit,deryni/cockpit,mvollmer/cockpit,garrett/cockpit,mvollmer/cockpit,moraleslazaro/cockpit,cockpit-project/cockpit,garrett/cockpit,cockpit-project/cockpit,deryni/cockpit,moraleslazaro/cockpit,moraleslazaro/cockpit,garrett/cockpit,cockpituous/cockpit,moraleslazaro/cockpit,garrett/cockpit,martinpitt/cockpit,cockpituous/cockpit,martinpitt/cockpit,deryni/cockpit,deryni/cockpit,cockpit-project/cockpit,garrett/cockpit,cockpituous/cockpit,cockpit-project/cockpit,deryni/cockpit,moraleslazaro/cockpit,cockpit-project/cockpit