Integration is failing to sync prospects because the relationship object contains a new key

[artpel]

Description

Currently, the tap-outreach connector only supports data and links keys in relationships. This change adds support for the meta key in relationships, that seems to be passed by Outreach for the prospects object

How to support this change

1. Modify process_records function in tap_outreach/sync.py to:

   • Accept meta as a valid key in relationships alongside data and links
   • Flatten meta data into the record with keys in the format {relationship_name}_{meta_key}
   • Preserve existing functionality for data and links keys

2. Update test cases in tests/unittests/test_exception_handling.py to:

   • Update error message to include meta as a valid key
   • Verify that invalid keys still raise appropriate exceptions