0024830: Remove redundant keyword 'mutable' in CDL declarations

Redundant keyword 'mutable' removed in CDL files.
In IGESConvGeom_GeomBuilder, unused methods MakeXY() and MakeXYZ() removed.
Method StepAP214_AutoDesignGroupAssignment::Init() replicating same method of the base class is removed as it causes CDL extraction error after above (seemingly irrelevant) changes.

src/GeomFill/GeomFill_BoundWithSurf.cdl

@@ -35,7 +35,7 @@ is
     Create(CurveOnSurf : CurveOnSurface from Adaptor3d;
            Tol3d       : Real from Standard;
     	   Tolang      : Real from Standard)
-    returns mutable BoundWithSurf from GeomFill;
+    returns BoundWithSurf from GeomFill;
     	---Purpose:
     	-- Constructs a boundary object defined by the 3d curve CurveOnSurf.
     	-- The surface to be filled along this boundary will be in the

src/GeomFill/GeomFill_CoonsAlgPatch.cdl

@@ -33,7 +33,7 @@ is
     --          constructed blending functions are linear.
     --  Warning: No control is done on the bounds.
     --          B1/B3 and B2/B4 must be same range and well oriented.
-    returns mutable CoonsAlgPatch  from  GeomFill;
+    returns CoonsAlgPatch  from  GeomFill;
 
     Func(me;
          f1,f2 : out Function from Law)

src/GeomFill/GeomFill_DegeneratedBound.cdl

@@ -28,7 +28,7 @@ is
     	   First, Last : Real from Standard;
            Tol3d       : Real from Standard;
     	   Tolang      : Real from Standard)
-    returns mutable DegeneratedBound from GeomFill;
+    returns DegeneratedBound from GeomFill;
 
     Value(me; 
           U : Real from Standard) 

src/GeomFill/GeomFill_Line.cdl

@@ -23,10 +23,10 @@ inherits TShared from MMgt
 
 is
 
-    Create returns mutable Line from GeomFill;
+    Create returns Line from GeomFill;
 
     Create(NbPoints : Integer from Standard)
-    returns mutable Line from GeomFill;
+    returns Line from GeomFill;
 
     NbPoints(me)
     returns Integer from Standard

src/GeomFill/GeomFill_SimpleBound.cdl

@@ -31,7 +31,7 @@ is
     Create(Curve  : HCurve from Adaptor3d;
            Tol3d  : Real from Standard;
     	   Tolang : Real from Standard)
-    returns mutable SimpleBound from GeomFill;
+    returns SimpleBound from GeomFill;
 
     	--- Purpose:
     	-- Constructs the boundary object defined by the 3d curve.

src/GeomFill/GeomFill_TgtOnCoons.cdl

@@ -27,7 +27,7 @@ uses
 is
     Create(K : CoonsAlgPatch from GeomFill;
            I : Integer from Standard)
-    returns mutable TgtOnCoons from GeomFill;
+    returns TgtOnCoons from GeomFill;
 
     Value(me; W : Real from Standard)
     returns Vec from gp;