Port app to swift 5 and arm64, fix some small bugs, update block lists. The research project that the app was originally written for has finished so the main substantive changes are to: (i) remove the project consent screen at first startup, (ii) disable upload of connection snippets (no connection data is uploaded now), (iii) change the default settings so that auto checking for updates is off (it can be turned back on in settings screen) - the effect of these changes is that now the only data sent by app is a short anonymous report if the app crashes (which hopefully never happens, certainly for last version I saw no crash reports). By request, I also changed the startup behaviour of the app so that the connections screen is no longer shown i.e. the app starts up silently and just displays its icon in the menu bar, clicking on the menu bar icon opens the connections screen etc as usual.