added methods MeshVertexCount and FaceVertexHandles for accessing mesh data from Python

[tkothadev]

Signed-off-by: T.J. Kotha [email protected]

What does this PR do?

Added two methods from the WhiteBoxToolApi class for Python reflection: MeshVertexCount and FaceVertexHandles.

These two provide minimal support for accessing mesh data from whitebox components, like in the following code excerpt:

vertlist = []
facelist = []

vertexCount = mesh.MeshVertexCount()
for i in range(vertexCount):
   vertHandle = azlmbr.object.construct('VertexHandle', i)
   new_vert = mesh.VertexPosition(vertHandle)
   vertlist.append([new_vert.x, new_vert.y, new_vert.z])

faceCount = mesh.MeshFaceCount()
for i in range(faceCount):
   faceHandle = azlmbr.object.construct('FaceHandle', i)
   new_face = mesh.FaceVertexHandles(faceHandle)
   new_list = []
   for f in new_face:
      new_list.append(f.Index())
   facelist.append(new_list)

#now we have minimal model mesh data to pass around as needed

I tested this in development in a test python script. It created the intended mesh data (a simple cube using initializeUnitCube) and transmitted it to an external location of my choosing. I verified the model was created correctly.