[Scenario] Revise activity tagging UI

Revise the user interface for managing Activity Tags and Activity Types from the Info View, as described in nasa/MCT-Plugins#129 and nasa/MCT-Plugins#130

Additionally resolves nasa/MCT-Plugins#132

It is believed that this resolves nasa/mct#249, although root cause of that issue is not definitive (that is, other sources of the observed latency there may exist)