show_transferee_as_caller cold transfer behavior

show_transferee_as_caller no longer toggles SIP REFER vs SIP INVITE in Cold Transfer options. Use the new cold_transfer_mode parameter instead; show_transferee_as_caller now only controls caller ID display under sip_invite.

Impacted API endpoints:

Create Vomyra LLM, Update Vomyra LLM, Create Conversation Flow, Update Conversation Flow, Create Conversation Flow Component, Update Conversation Flow Component - field: show_transferee_as_caller