0024784: Move documentation in CDL files to proper location

Mostly duplicated comments were removed and missing ones were moved
into dedicated class CDL files.
Some more duplicated comments were removed from CDL files.
Correction of merge

src/MgtBRep/MgtBRep.cdl

@@ -81,11 +81,9 @@ is
     -- ---------
 
     class TranslateTool;
-	---Purpose: Auxiliary class used to call the MgtTopoDS methods.
-    
+
     class TranslateTool1;
-	---Purpose: Auxiliary class used to call the MgtTopoDS methods.
-    
+
 
     -- ---------------
     -- Package Methods

src/MgtBRep/MgtBRep_TranslateTool.cdl

@@ -21,6 +21,7 @@ class TranslateTool from MgtBRep inherits TranslateTool from MgtTopoDS
 
 	---Purpose: The TranslateTool class is provided to support the
 	--          translation of BRep topological data structures.
+	--          Used to call the MgtTopoDS methods.
 uses
 
     TransientPersistentMap from PTColStd,

src/MgtBRep/MgtBRep_TranslateTool1.cdl

@@ -24,6 +24,7 @@ class TranslateTool1 from MgtBRep inherits TranslateTool1 from MgtTopoDS
 
 	---Purpose: The TranslateTool1 class is provided to support the
 	--          translation of BRep topological data structures.
+	--          Used to call the MgtTopoDS methods.
 uses
 
     TransientPersistentMap from PTColStd,