BIM: ignore FreeCAD groups for IFC export, controlled by a user preference (#21583)

* Add .db extension to git ignore list

* BIM: new feature - add ignore groups option on IFC exports

* BIM: create generic get_architectural_contents function

.gitignore

@@ -25,6 +25,8 @@
 *.o
 *.orig
 *.output
+# Ignore .db files created by Qt Designer when editing .ui files
+*.db
 qrc_*.cpp
 BuildLog.htm
 cmake_install.cmake