Fix remaining deprecations and related issues

Fix the following deprecation related issues

1. ci: switch to Fedora 32 for CI ( and enable daap plugin build )
2. audioscrobbler: Fix crash by using G_ADD_PRIVATE_DYNAMIC() for GTypeModule types ( Closes: #1774 (closed) )
3. add util function rb_get_application_window() to get toplevel app window
4. audioscrobbler: fix application exit by using rb_get_application_window()
5. audioscrobbler: delegate opening authorization uri in profile page rather than in account object
6. use rb_get_application_window() to get toplevel app window
7. fix import-dialog crash when import button is pressed by adding private offset
8. replace deprecated pango_find_base_dir() with fribidi equivalent ( tested with Hebrew and Arabic for RTL )

Segmented bar gdk_cairo_create deprecation is covered in !73.

So, I think all deprecation warnings have been handled for now.