Python: Allow enums to be passed in to on_function_result. Improve handling FRC result so it can be hashed. - #10316

…ndling FRC result so it can be hashed. (microsoft#10316)

### Motivation and Context

Two topics in this PR:
- A request to be able to pass in Enums to the Python process
`on_function_result`, instead of just strings.
- There were some custom types (Pydantic models) that were unable to
hash during an agent group chat. One could mark the model `frozen` so
that it is hashable; however, we should add better handling in our code,
in case a dev doesn't want to do that.

<!-- Thank you for your contribution to the semantic-kernel repo!
Please help reviewers and future users, providing the following
information:
  1. Why is this change required?
  2. What problem does it solve?
  3. What scenario does it contribute to?
  4. If it fixes an open issue, please link to the issue here.
-->

### Description

This PR:
- checks if the function name in `on_function_result` in our process
framework is an enum, if so, convert to a string.
- improves the parsing of the `result` in `FunctionResultContent` so
that it can be included in the hash function during an agent group chat.
Adding tests to handle multiple different scenarios.
- Closes microsoft#10299 
- Closes microsoft#10305

<!-- Describe your changes, the overall approach, the underlying design.
These notes will help understanding how your code works. Thanks! -->

### Contribution Checklist

<!-- Before submitting this PR, please make sure: -->

- [X] The code builds clean without any errors or warnings
- [X] The PR follows the [SK Contribution
Guidelines](https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md)
and the [pre-submission formatting
script](https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md#development-scripts)
raises no violations
- [X] All unit tests pass, and I have added new tests where possible
- [X] I didn't break anyone 😄