Use libTaskManager for identifying the browser
Leverages its heuristic for finding desktop files and lets us support pretty much any browser without the need to hardcode a mapping.
The browser still sends us its environment as a fallback. It is also used so we at least have a baseline of "this is a Firefox derivate" or "a Chromium browser" since some parts of the host react differently based on the environment.
Alternative to !17 (closed)
It detects Microsoft Edge and Chromium dev properly now.
It does not detect a Waterfox from my Downloads folder but it obv can't detect browsers that don't have a service installed in a known location.
Also drop the Settings DBus service which won't be needed anymore once tabsrunner is ported to DBus runner.
I think the organization name and domain aren't really used by us? I think AppDataLocation or someting might use them?