v3.0.0 - suggestion - Modify sysex related signatures for perf gains

[zfields]

void FirmataClass::sendSysex(byte command, byte bytec, byte *bytev)

typedef void (*sysexCallbackFunction)(uint8_t command, uint8_t argc, uint8_t *argv); in FirmataParser

Since parameter bytec is used for counting the number of bytes, it would be great to see this switched up to a size_t (a.k.a. unsigned int). This is the native integer size for the architecture and therefore the most performant.

[v3.0.0][suggestion]