FBX -> Scene, part 2. Code changes, file renames (#1704)

* First pass FBX -> Scene File conversion.
This is the simple pass, minimizing code changes and focused on comments.

Signed-off-by: stankowi <4838196+AMZN-stankowi@users.noreply.github.com>

* Step 1 of part 2 of the FBX -> Scene rename

Signed-off-by: stankowi <4838196+AMZN-stankowi@users.noreply.github.com>

* Renaming FbxSceneBuilder folder to SceneBuilder

Signed-off-by: stankowi <4838196+AMZN-stankowi@users.noreply.github.com>

* Renamed files

Signed-off-by: stankowi <4838196+AMZN-stankowi@users.noreply.github.com>

* More FBX -> Scene

Signed-off-by: stankowi <4838196+AMZN-stankowi@users.noreply.github.com>

Code/Tools/SceneAPI/SDKWrapper/AssImpNodeWrapper.cpp

@@ -15,8 +15,8 @@ namespace AZ
 {
     namespace AssImpSDKWrapper
     {
-        AssImpNodeWrapper::AssImpNodeWrapper(aiNode* fbxNode)
-            :SDKNode::NodeWrapper(fbxNode)
+        AssImpNodeWrapper::AssImpNodeWrapper(aiNode* sourceNode)
+            :SDKNode::NodeWrapper(sourceNode)
         {
             AZ_Assert(m_assImpNode, "Asset Importer Node cannot be null");
         }