Log transport in STIX - to review (2.2?)

[adulau]

https://github.com/opencybersecurityalliance/stix-extensions/blob/main/2.x/SDO/x-oca-event.md

[adulau]

During the TC, we had a discussion if there is anything missing (such as field) compared to the event at OCSF https://github.com/ocsf/ocsf-schema/blob/aa7a4201437be285cbd434b97b643ded04d2e093/events/base_event.json#L2

[adulau]

Related to #1

[adulau]

A proposal in #340