Expose Patch Reversion in the Web Client

The web client will need to expose the ability to revert a patch which was successfully applied to one or more services. Patch upgrades allows one or more services to effectively be "patched" to a new version. Some facts:

• Patching will only apply to the current stack. If the cluster was installed with HDP 2.5, then all patches must be scoped to 2.5.x.y - you cannot patch outside the stack.

• Each service/component now exposes the repository version they are on.

The following work should be scoped in this Jira. If the scope turns out to be too great, then it can be broken up into several JIras:

• The stacks and versions page will change to show multiple "CURRENT" stacks.
• The most recent patch will be able to be reverted. The revert button will only show for the newest applied patch. Once reverted, the prior patch can be reverted now.
• If a full stack upgrade is performed, then the bar is reset, regardless the version upgraded to.