add plate element

[obucklin]

This adds the plate element to Compas_timber. This is concieved as an extrusion with a boundary curve(Polyline) and a thickness. A vector input serves to switch the side towards which the plate is extruded. This has been tested with the Drill feature to ensure the Brep is oriented correctly and the boolean subtraction functions properly. Certain attributes are not yet implemented fully, such as the bounding box. TimberModel has been updated to include the TimberModel.plates property.

I will continue to change other modules to remove references to beam in exchange for more generic element types when appropriate.

What type of change is this?

• [ ] Bug fix in a backwards-compatible manner.
• [x] New feature in a backwards-compatible manner.
• [ ] Breaking change: bug fix or new feature that involve incompatible API changes.
• [ ] Other (e.g. doc update, configuration, etc)

Checklist

invokes don't seem to be working on mac, I will run these when I get back to my PC.

• [x] I added a line to the CHANGELOG.md file in the Unreleased section under the most fitting heading (e.g. Added, Changed, Removed).
• [ ] I ran all tests on my computer and it's all green (i.e. invoke test).
• [x] I ran lint on my computer and there are no errors (i.e. invoke lint).
• [x] I added new functions/classes and made them available on a second-level import, e.g. compas_timber.datastructures.Beam.
• [ ] I have added tests that prove my fix is effective or that my feature works.
• [ ] I have added necessary documentation (if appropriate)

[obucklin]

• have you had a look at https://github.com/BlockResearchGroup/compas_model/blob/main/src/compas_model/elements/plate.py? maybe it's not right for us but might be worth it to have a look.

I had not seen that. the two polygons as faces seems like a good way to do it. I will try it out and see how it works. My only concern is whether their shape (a mesh) works with the CT features. Maybe you know...