Normalize notes about "row by row packing"?

[amilan17]

These two notes look the same. Can we make them one note?

31	Group lengths have no meaning for row by row packing, where groups are coordinate lines (so the grid description section and possibly the bit-map section are enough); for consistency, associated field width and reference should then be encoded as 0.
32	Group lengths have no meaning for row by row packing; for consistency, associated field width should then been coded as 0. So no specific test for row by row case is mandatory at decoding software level to handle encoding/decoding of group descriptors.

Found in:

• Data representation template 5.2 – Grid point data – complex packing
• Data template 7.2 – Grid point data – complex packing

Originally posted by @amilan17 in #118 (comment)