UI: Just use json directly for service lookups

This commit accomplishes three different things:

- Makes it much less difficult to communicate service settings
  between the UI and the plugin.

- Refactors some code and makes it cleaner and easier to modify to our
  needs (although there is still a lot of work to do on that front
  because of heavy code duplication issues between auto-config and the
  stream settings pane).

- Significantly reatly reduces the number of times the json file has to
  be opened and parsed.

This also kind of denotes a bit of a failure on the plugin communication
aspect. The properties system is too limited and jank for a lot of
things we would like to do at times.

UI/CMakeLists.txt

@@ -140,6 +140,8 @@ target_sources(
           crash-report.cpp
           crash-report.hpp
           display-helpers.hpp
+          streaming-helpers.cpp
+          streaming-helpers.hpp
           platform.hpp
           qt-display.cpp
           qt-display.hpp