ReACT Agent should be consistent with Agent

[hardikjshah]

React agent takes custom args and builds a config under the hood.
This means there is no easy way to pass overrides to the agent config ( eg. #148 )

We should create React Agents similar to Agents via

agent = ReActAgent(client, agent_config, client_tools)

and do all the specific setup logic around system prompt, tool parsing, etc in the ReActAgent class.

[MichaelClifford]

@hardikjshah I was about to open a similar Issue 😄 would you mind assigning this issue to me, happy to work in it.