Add debug variable messages

[rbonghi]

Now the packet communication doesn't have a general purpose message to send variables to debug. I will add in serial protocol a new type of messages to send debug messages.

• [ ] Write a B type of message to put all type of messages;
• [ ] Write a list of messages, example:

typedef int8_t debug8;
typedef int16_t debug16;
//...
typedef float debug_float;
//..
//Number association for standard messages
#define DEBUG8 0
#define DEBUG16 1
// ...
#define DEBUG_FLOAT n
//...

Finally I will write a new hash map with list of type debug messages:

#define INITIALIZE_HASHMAP_DEBUG hashmap_default[DEBUG8] = LNG_DEBUG8;    \
                                   //....
                                   hashmap_default[DEBUG_FLOAT] = LNG_DEBUG_FLOAT;