New browser engine reports based on new browser engine detection of DeviceDetector

*First step of removing old UserSettings stuff (refs #3962)*

- updates DeviceDetector to latest version (and adds missing browser/os icons)
- old BrowserType reports (UserSettings plugin) has been removed / replaced with new browser engine reports in DeviceDetection plugin
- those reports will be much more accurate as before the detection was only based on a browser name > browser engine mapping
- browser eninge is now stored in a new db field
- browser engine is also available for segmentation
I've thought if it would make sense to add an BC test at that point. If we are going to remove UserSettings completely and use the 'Api-renaming' to have the UserSettings-API still callable, I guess it won't make sense to add test for each method at that point. Maybe it would be enough to add a simple test, that just checks if the methods are still callable. Instead of testing the content of the old methods we should add tests for the new methods... what do you think?