Fix bug where xform fields that were not specified for motion interpolation were still getting interpolated.

Carry logic from this fix to writing Xform Xmls as well.

Motion was not supported on some Xform fields as it was originally copied from flam3. Allow it on all but xaos now.

Fix clamping range for m_ColorSpeed at the end of ApplyMotion() to match the values we accept elsewhere.

Source/Ember/EmberDefines.h

@@ -74,6 +74,7 @@ namespace EmberNs
 #define TMAX std::numeric_limits<T>::max()
 #define FLOAT_MAX_TAN 8388607.0f
 #define FLOAT_MIN_TAN -FLOAT_MAX_TAN
+#define EMPTYFIELD -9999
 typedef std::chrono::high_resolution_clock Clock;
 
 #ifndef byte