Remove function calling

[nalbion]

Remove function calling so that we can properly test other LLMs

[nalbion]

Will need to revert back from fabulous to colored so that the code can be ran and debugged on Windows

jart/fabulous#21

[nalbion]

This is a model trained for function calling, based on Llama 2 - https://github.com/MeetKai/functionary

[nalbion]

@LeonOstrez

In Developer.set_up_environment() there is code (which is currently unreachable, due to a return at line 312) which uses function calling for one of the few non-trivial use cases. It calls execute_command_and_check_cli_response() and introduces send_convo which creates a bit of a mess.

...I'd like to refactor AgentConvo.postprecess_response() into function_calling.process_json_response() to make it clear that it's the complement to function_calling.add_function_calls_to_request().

I'm going to refactor the part of Developer that sends development/env_setup/install_next_technology.prompt into a separate method and align it more with Developer.implement_step()