Add UI for observing outcome when deploying policies in "dry run" mode

As part of https://github.com/DependencyTrack/hyades/issues/957, we identified that it would be good to have a "dry run" mode for policies. This mode would evaluate policies, but not apply their associated action.

Initially, this functionality is implemented using application logs. However, long-term, we can't expect users to observe logs. We should have a UI integration that provides this information instead.

The granularity of the information being displayed is still subject for discussion. But generally, the following would be nice to have:

* Number of affected projects
* Number of affected components
* Number of affected findings
* Potentially with additional aggregates, as in "avg. findings affected per component / project"