new map tool to select single feature
use a specific class for the widget (to be used as a custom widget), rename old _widget to _wrapper
add new configuration for the widgets: line edit and button to select on map
use map tool from widget to select new related feature
give the dialog as a parent
Convert exec -> show
Simplify code
Style NULL value
Show dialog after identify and react to deactivated signal
Fix crash if relation is not properly set up
Fix valueChanged signal (needs to emit foreign key value, not fid)
Fix warning (the layout parent is automatically assigned when it's added to mTopLayout)
Search containing attribute dialog by object name
Should be fixed in the future by proper methods in the QgsAttributeEditorContext
Save maptool to member variable instead of local
followup ad5aa30
make button disable instead of hidden
scale and highlight feature