Added operator to add psets to all selected objects. (IfcOpenShell#1805)

* first attempt

* Accommodate object vs non-object psets, and directly fetch applicable pset names

Co-authored-by: Dion Moult <[email protected]>

WIP refactor of geometry for stabilisation and optimisation. Switch r…

…epresentation now done.

Refactor misc functions into new misc module for better organisation.

Fix IfcOpenShell#1801. Fix bug where importing multiple assets sharin…

…g an already imported material fails.

Building storeys now show a derived storey height so you don't need t…

…o do math

Fix IfcOpenShell#1796. Fix bug where duplicating a collection messes …

…up the collection tree.

Fix IfcOpenShell#1793. Whoops.

New usecase for adding conversion based units

First batch of Pset Templates tests (IfcOpenShell#1772)

Fix and test importing style attributes twice (IfcOpenShell#1784)

* Test importing surface attributes twice

* Fix style attributes not cleared when re-importing