Move RADIX_TYPE enum into its own header (#25)

This change moves the RADIX_TYPE enum into its own header. This resolves a compilation error and reduces the dependency graph by allowing RadixToStringConverter to include just the enum header rather than the entire CalcEngine header.

Change verified by ensuring Calculator build locally.

src/CalcManager/Header Files/CalcEngine.h

@@ -20,6 +20,7 @@
 #include "../Command.h"
 #include "../CalculatorVector.h"
 #include "../ExpressionCommand.h"
+#include "RadixType.h"
 #include "History.h"  // for History Collector
 #include "CalcInput.h"
 #include "ICalcDisplay.h"
@@ -38,15 +39,6 @@ enum eNUM_WIDTH {
 typedef enum eNUM_WIDTH NUM_WIDTH;
 static constexpr size_t NUM_WIDTH_LENGTH = 4;
 
-// This is expected to be in same order as IDM_HEX, IDM_DEC, IDM_OCT, IDM_BIN
-enum eRADIX_TYPE {
-    HEX_RADIX,
-    DEC_RADIX,
-    OCT_RADIX,
-    BIN_RADIX
-};
-typedef enum eRADIX_TYPE RADIX_TYPE;
-
 namespace CalculationManager
 {
     class IResourceProvider;