When a new footprint is created, CreateNewModule() added it to a dummy
board in the footprint editor. If a footprint was indeed created (the
action has not been aborted) then the dummy board was cleared,
destroying the just created footprint. Also, the new footprint is later
added with AddModuleToBoard() call.
Fixes: lp:1761052
* https://bugs.launchpad.net/kicad/+bug/1761052
Add a library selector to the save dialog. Initialize it to the
footprint's library. This way a straigh-up save will do what's
expected.
However, the user can still select the active library (or any
other library) if they really did want to move the footprint.
Fixes: lp:1750918
* https://bugs.launchpad.net/kicad/+bug/1750918