Add hosted element area to parameters in Revit.

[ks-cph]

Description & motivation

Refers to Issue #3530
This change adds the Area of hosted elements within a host to a parameter. So far, no such parameter is available. This becomes especially important for windows and doors where the Area of removed elements can be essential. For instance, prefabricated timber elements are normally produced as a whole, and then these parts are removed, which is somewhat wasteful (even though they may be re-used).

Others will benefit from this change as such essential information is not yet available in Speckle.

Changes:

• Add a method to get the Area of a Hosted element in a Host
• Add the Area as a new Parameter to the Base object

To-do before merge:

We chose to use the approach described in https://thebuildingcoder.typepad.com/blog/2015/03/ifcexportutils-methods-determine-door-and-window-area.html. However, this solution refers to the Revit.APIIFC.dll which is not part of the Revit Converters or Dynamo Converters, yet.

• The code requires the RevitAPIIFC.dll

Validation of changes:

The contribution has been verified with several Revit models where windows and doors are added to walls.

Checklist:

• My pull request follows the guidelines in the Contributing guide?
• My pull request does not duplicate any other open Pull Requests for the same update/change?
• My commits are related to the pull request and do not amend unrelated code or documentation.
• My code follows a similar style to existing code.
• I have added appropriate tests.
• I have updated or added relevant documentation.