[connectors-sdk] Add missing values in `RelationshipType` enum

[Powlinett]

Description

Currently connectors-sdk emits warnings for valid relationship type, see Checkfirst PR for instance: #6032 (review)

Expected output

The enum RelationshipType should contain all the valid values according to STIX2.1 spec or OpenCTI and no warnings should be emitted when instantiating valid Relationship objects.