Fix left out invalid mesh data blocks and fix failing geom core test (after fcee54c)

src/bonsai/test/bim/feature/geometry.feature

@@ -102,8 +102,10 @@ Scenario: Remove representation - remove an active representation
     And I set "scene.BIMRootProperties.ifc_class" to "IfcWall"
     And I press "bim.assign_class"
     When the variable "representation_body" is "{ifc}.by_type('IfcShapeRepresentation')[0].id()"
+    And the variable "representation_context" is "{ifc}.by_type('IfcShapeRepresentation')[0].ContextOfItems.id()"
     And I press "bim.remove_representation(representation_id={representation_body})"
     Then the object "IfcWall/Cube" has no data
+    And the mesh "{representation_context}/{representation_body}" does not exist
 
 Scenario: Remove representation - remove an unloaded representation
     Given an empty IFC project

src/bonsai/test/bim/test_feature.py

@@ -1194,6 +1194,11 @@ def the_material_name_does_not_exist(name):
     assert bpy.data.materials.get(name) is None, "Material exists"
 
 
+@then(parsers.parse('the mesh "{name}" does not exist'))
+def the_mesh_name_does_not_exist(name: str) -> None:
+    assert bpy.data.meshes.get(name) is None, f"Mesh '{name}' exists"
+
+
 def get_ifc_material_by_name(name: str) -> Union[ifcopenshell.entity_instance, None]:
     ifc_file = tool.Ifc.get()
     material = next((m for m in ifc_file.by_type("IfcMaterial") if m.Name == name), None)