Parser: use read_bytes() in the extract_number function
Parser: use read_bytes() in the extract_number function

The extract_length() function is only used in string context, so rename
accordingly.

Signed-off-by: Thiago Macieira <0ed1648d92ca0373297a182b1dba1b974ad10d88@intel.com>

intel/tinycbor,intel/tinycbor,intel/tinycbor,intel/tinycbor