Add parse support for these types:
- SIG: RFC4034/3755/2535/2536/2537/2931/3008/3110
- KEY: RFC4034/3755/2535/2536/2537/2539/3008/3110
- LOC: RFC1876
- NAPTR: RFC2915/2168/3403
- KX: RFC2230
- CERT: RFC4398
- APL: RFC3123
- SSHFP: RFC4255
- IPSECKEY: RFC4025
- DHCID: RFC4701
- NSEC3: RFC5155
- NSEC3PARAM: RFC5155
- TLSA: RFC6698
- SMIMEA: RFC8162
- HIP: RFC8005
- OPENPGPKEY: RFC7929
- CSYNC: RFC7477
- TKEY: RFC2930
- TSIG: RFC2845
- URI: RFC7553
- CAA: RFC8659
See also TODOs in rdata.rs
.