Implement missing 'ForceOff' (Kill) option for stopping VM

[Gerard Braad]

libhvee/pkg/hypervctl/vm.go

Line 231 in 3777cda

 In("Force", false). 

[Brent Baude]

@gbraad see #50

[Gerard Braad]

Can be closed with a dup notice.

Was an observation of missing functionality as a force is often required in the case of OCP: cluster stopped but VM is just taking its time.

[Gerard Braad]

Duplicate of #50