E.g. previously set_element_value with query "material.item.Material.Name" would fail with error "Material property is expecting an IFC entity and not a string".
But now it will detect that "Material" property is not a last key in the query and will pass `.Material` value forward and try to set it's `.Name` attribute with value.
The main goal is to make sure get_element_value and set_element_value would have a same result for same queries.
removed part of test_append_two_type_products_sharing_the_same_material_indirectly_via_a_material_set for ifc2x3 compatibility and removed part is already tested in test_append_two_type_products_sharing_the_same_material_with_properties
When some test was creating an element and then removing it, it would also remove user and application as they wasn't used anywhere else.
`ifcopenshell.util.element.remove_deep2(file, history)` we use in every api for element deletion can possibly remove user and application which can be unsafe if `get_user` is returning some specific entity that then will become invalid.
Also fixed tests breaking due ifcownerhistory and user/application appearing in ifc2x3.
it was creating new applications and users every time `ifcopenshell.api.owner.settings.get_user` or `ifcopenshell.api.owner.settings.get_application` was called
ifcpatch ConvertLengthUnit - change used units from plural to singular names, to make it consistent across the api
more test coverage - test converting to more units and back from them
added temporary support for old version with warnings:
WARNING. `spatial.remove_container` api method is deprecated and should be replaced with spatial.unassign_container
WARNING. `product` argument is deprecated for API method "spatial.remove_container" and should be replaced with `products`.
Dion Moult