Cherrypicking various fixes: (poppler 21.11.0 build issues, win32 themeing, auto-switching with tablet, test fix with dbus, measure lpe crashfix)

. Will link to MRs...

By commit (latest commit first):

1. 2d472a03 Fix build with poppler 21.11.0 : as commit message states !3622 (merged), #2906 (closed)
2. 3e771263 add expander arrow to win32 theme css : as commit message states !3585 (merged), #2876 (closed)
3. 4cc4cb4a Fix tablet tool auto-switching for tablet devices : as commit message states, broken since 1.0 !3578 (merged)
4. fad9b51e check for empty paths before checking if they are closed fix #2725 (closed) : some paths have empty subpaths (e.g. M 0 0 H 15 M 20 20 Z) and previously crashed in Measure LPE applied !3553 (merged)
5. 7e66d4ba Avoid initializing DBUS twice. : avoids crash running inkscape --actions=action-list if built with DBUS !3574 (merged) #2813 (closed)