[FEATURE] Support for pre and post hooks (including observability capabilities)

[tpiperatgod]

Since the current groundwork for supporting the ofn v1beta2 api is complete, we need to add pre and post hooks for ff-python, also the observability capabilities.

[tpiperatgod]

/assign

[benjaminhuo]

Maybe we can release a builder without the pre/post hook function for now?