ssl-utils: dissect the certificate type TLS extension

This analyses the certificate type extensions and then stores the
certificate type in the ssl session. This way we can later show the
certificate in the correct from.

This is described in this draft:
https://tools.ietf.org/html/draft-ietf-tls-oob-pubkey-11

Change-Id: Ifdda165807bc29f1fc138da000a9a538ecd18b6e
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
ssl/dtls: add support for Raw Public keys

Instead of X.509 certificates now also Raw public keys are supported
and shown correctly.

This is described in this draft:
https://tools.ietf.org/html/draft-ietf-tls-oob-pubkey-11

Change-Id: Ibe7610aace31a19791b02e71ccd8d9ceb8cf979d
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>