Unify compare/drift actions

[jzigmund]

As I've fixed #773 and #775 noticed that controllers (i.e. host vs vm_infra) are not using the same flow to handle the comparison requests.
For Hosts are used ApplicationController#compare_miq (as HTML) vs. for VMs is used VmInfraController#x_button as JS what can cause other bugs. Also would be useful to refactor generating html without calling html_safe as it's not safe [1]

Created Issue with @skateman 's cooperation

[1] - http://www.rubydoc.info/gems/rubocop/0.41.2/RuboCop/Cop/Rails/OutputSafety

[miq-bot]

This issue has been automatically marked as stale because it has not been updated for at least 6 months.

If you can still reproduce this issue on the current release or on master, please reply with all of the information you have about it in order to keep the issue open.

Thank you for all your contributions!

[JPrause]

@h-kataria is this still a valid issue? If yes, lease remove the stale label. If not can you close.
If there's no update by next week, I'll be closing this issue.