lego: add MxDSType enum, add it to all ctors, refactor MxDSObject (#73)

* lego: add MxDSType enum, add to all ctors

* refactor header

* re-type members

* add size assert for MxDSObject

* fix Parse param

* fix types

LEGO1/mxdssound.cpp

@@ -4,10 +4,10 @@
 MxDSSound::MxDSSound()
 {
   // TODO
+  this->SetType(MxDSType_Sound);
 }
 
 // OFFSET: LEGO1 0x100c9470
 MxDSSound::~MxDSSound()
 {
-  // TODO
 }