Introduce activity_sub_type

<> API Reference

Activities API

• The GET /activities response payload now includes a new optional field activity_sub_type. This field provides a more detailed classification, in addition to the existing activity_type field.
• A new entry_type, OPCA (Options Corporate Action), has been introduced to improve the classification and reporting of options corporate action activities.
• For further details, refer to the Activities API documentation:
  • Activities API - Trading
  • Activities API - Broker