[API] remove QgsVectorDataProvider::enableGeometrylessFeatures(bool)

Geometryless features are not skipped by default anymore.
Fix #7549 (selection color is now stored in QgsRendererContext)
Tweak margins on attribute table
Merge remote-tracking branch 'origin/master' into qgisMapserver_proxy
Merge remote-tracking branch 'mygithub/qgisMapserver_proxy' into qgisMapserver_proxy