utf8ToUint16
Function converts a byte array encoded in utf8 to uint16. Each byte is encoded in utf8 as follows:
1 byte (0xxxxxxx in uint16) - 0xxxxxxx
2 bytes (00000yyy yyxxxxxx in uint16) - 110yyyyy 10xxxxxx
3 bytes (zzzzyyyy yyxxxxxx in uint16) - 1110zzzz 10yyyyyy 10xxxxxx
Return
Byte Array - uint16 representation of the utf8 array.