Remove `prompt_parameters_resolver` from the `Agent`

[bilgeyucel]

Is your feature request related to a problem? Please describe. It isn't straightforward to understand what prompt_parameters_resolver does and the possible attributes to use in it. e.g. I can't know if I have access to AgentStep or Agent attributes in the resolver unless I check the code.

Describe the solution you'd like Remove prompt_parameters_resolver parameter from the Agent completely and handle prompt variables in _plan method of the Agent. We can reserve query, tool_names, tool_names_with_descriptions, transcript and memory words for their corresponding values and warn users if any other prompt variables are used. We can think of the variable names and explain their values in documentation and tutorials

Describe alternatives you've considered Leave it as it is and solve this with V2

Additional context N/A