rewrite and reoganize tools functions

* create stdext namespace which contains additional C++ algorithms
* organize stdext in string, math, cast and exception utilities

src/framework/const.h

@@ -23,8 +23,6 @@
 #ifndef FRAMEWORK_CONST_H
 #define FRAMEWORK_CONST_H
 
-#include "util/types.h"
-
 #define DEG_TO_RAD (acos(-1)/180.0)
 #define RAD_TO_DEC (180.0/acos(-1))
 
@@ -44,7 +42,7 @@ namespace Fw
     constexpr float pi = 3.14159265;
     constexpr float MIN_ALPHA = 0.003f;
 
-    enum Key : uint8 {
+    enum Key : unsigned char {
         KeyUnknown = 0,
         KeyEscape = 1,
         KeyTab = 2,