Description of problem:

The hosted-engine-setup ansible code allows pausing the deploy process at a certain point (after adding the host to the engine):

https://github.com/oVirt/ovirt-ansible-hosted-engine-setup/blob/master/README.md#make-changes-in-the-engine-vm-during-the-deployment

We should expose that in the cockpit UI:

1. Either directly, add a checkbox that sets the ansible var 'he_pause_host' to True, or

2. Allowing somehow setting arbitrary ansible vars, to allow configuring things we didn't add a specific cockpit gui element for but did allow controlling via ansible vars.

We should probably do both.

I asked Simone in private, and he replied, for (1.):

We have to add something like:
                pauseHost: {
                    name: "PAUSE_HOST",
                    ansibleVarName: "he_pause_host",
                    ansiblePhasesUsed: [phases.BOOTSTRAP_VM],
                    description: "Pause host",
                    value: false,
                    type: types.BOOLEAN,
                    showInReview: false,
                    uiStage: "",
                    useInAnswerFile: false,
                    required: false
                },

here:
https://github.com/oVirt/cockpit-ovirt/blob/master/dashboard/src/helpers/HostedEngineSetupUtil.js#L25

Then add a checkbox here:
https://github.com/oVirt/cockpit-ovirt/blob/master/dashboard/src/components/HostedEngineSetup/VmStep/HeWizardVm.js#L488
 
and a handler here https://github.com/oVirt/cockpit-ovirt/blob/master/dashboard/src/components/HostedEngineSetup/VmStep/HeWizardVmContainer.js

to set the value of he_pause_host according to the value of the checkbox.