Add support to JA3s

[jgvt]

Hello,

It may be useful to add support to JA3S to MISP with the same format that JA3 which is already implemented :

attributes, first-seen, ip-dst, ip-src, ja3-fingerprint-md5, ja3s-fingerprint-md5, last-seen.

ja3s-definition.json.txt

[adulau]

Thank you for the contribution. It's now in the default object template repository. (sorry I missed your contribution as it was not a pull-request)