Input, Gui: total events complementarity on all levels (#681)

* Cli: add missing const in cli_write.
* Gui, Input: bit fields based key complementarity on all levels, key and type names API.
* Gui: minor cleanup of bit filed usage

applications/input/input.h

@@ -18,3 +18,15 @@ typedef struct {
     InputKey key;
     InputType type;
 } InputEvent;
+
+/** Get human readable input key name
+ * @param key - InputKey
+ * @return string
+ */
+const char* input_get_key_name(InputKey key);
+
+/** Get human readable input type name
+ * @param type - InputType
+ * @return string
+ */
+const char* input_get_type_name(InputType type);