FEAT: Refactor PAIR to be a special instance of TAP

[rlundeen2]

This PR refactors PAIR to be a special instance of TAP. This simplifies a lot of logic. But the functionality should be identical as it was (the system prompts should be the same)

• FEAT: refactoring PAIR to just be a specific case of TAP. The system prompts and turns should be identical, but maintenance is easier and we get certain features (like converters, better print_conversation that can display images)
• FEAT: Adding desired_response_prefix as an option for TAP
• FIX: generalizing multi-turn print_messages for different formats
• MAINT: added tests for print_conversation_async

Note: Currently I am removing the single_turn option for PAIR, but will add it back soon for all multi-turn-orchestrators

Tests:

• Ran TAP and PAIR notebooks