[idea] Rename iso18.h or allow including other ISO 18000

[nflatrea]

iso18.h / iso18.c in the codebase implements ISO 18092 (NFC-DEP / NFC-F) for FeliCa
The "iso18" naming is a shorthand for ISO 18092, not a generic "ISO 18000" umbrella,
my issue here is that i'm tinkering with ISO 18000-3 MODE 3 class tags and this naming creates quite confusion.

We have two options here:

1. We keep iso18.h for FeliCa / ISO 18092 but we also include other iso18 families, which is not the best
2. We keep each class separated ( iso18092.h for NFC p2p / iso180003.h for RFID item level ID )

Don't have the answer, tweaking my own based on 2nd opt

[iceman1001]

Keep them separate. I am also looking at 3m3... ;)