ssl: use SslSession

Use the struct SslSession instead of passing the tls version and cipher
to each function.

Change-Id: I19b163913f8f6521a34d94d130e2ae74546a615a
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Reviewed-on: https://code.wireshark.org/review/1821
Reviewed-by: Alexis La Goutte <alexis.lagoutte@gmail.com>
(cherry picked from commit 13e4f777c763e22a260638445d7395687d787b54)
Reviewed-on: https://code.wireshark.org/review/2814
Reviewed-by: Anders Broman <a.broman58@gmail.com>