style: update workflow activity names

[sicoyle]

Currently in durable.py we have a mix on function names called within Dapr Workflow Activities. For stylistic-sake, I want the function names to not include an underscore prefix. I also renamed a few...

Acceptance criteria:

• _load_tools -> load_tools
• _get_available_agents -> get_team_members
• _initialize_orchestration -> initialize_orchestration
• _validate_next_step -> validate_step
• _select_next_action -> select_next_task
• _parse_progress -> evaluate_progress
• _save_plan_message -> save_plan
• _process_orchestration_response -> handle_response
• _should_continue_orchestration -> check_completion
• _finalize_orchestration -> finalize_orchestration
• broadcast_message_to_agents -> broadcast_to_team
• send_response_back -> return_response

Thoughts @CasperGN

[CasperGN]

I think this is good. Python isn't strict about private methods anyway so it'll be nicer viewing these wf activites like the proposed

[sicoyle]

@vbhavh would you like first dibs here instead? 🌞 (regarding #474 (comment))

[Faakhir30]

I'd like to work on this one.