Unification of Element GeometryObject extraction

### Fix

There were a number of out of date methods for extracting Geometry from Revit Elements.  I've removed the Outdated ones.  Now there is only one, `InternalGeometry.`  Notably, this also fixes the issue encountered in #2487, as this method correctly translates instance geometry.

I've also tweaked the AssemblyInfo file for RevitNodes so it exposes it's internals to RevitNodesTests.  This allows me to remove the attribute from `InternalGeometry` and correctly set this method as `internal.`

### Tests

There is a new unit test for #2487 in RevitNodesTests.

### Reviewer

@Randy-Ma