Simplification of 'name'

[gselander]

Addresses #172. For discussion.

• Makes use of the CBOR tag for MAC addresses which didn't exist at the time when the original text was written.

• Does not make use of the CBOR tags for IPv4/v6 addresses, but removes the arbitrary prefix '00' for encoding of byte strings, since we can now distinguish from EUI-64 by above.

[gselander]

@cabo noted on the COSE list that CBOR tag 23 encodes upper case hex text strings. This is a possible completeness addition, but makes processing slightly more complicated, contradicting the original intent with this PR.

(Text to add:

*If the text string has an even length {{{≥}}} 2 and contains only the symbols '0'–'9' or 'A'–'H', it is encoded as a CBOR tagged byte string using the CBOR tag 23, see {{Section 3.4.5.2 of RFC8949}}.
)