[Feature Request] Get the input of chat/prompt of LLM node

Is your feature request related to a problem? Please describe.
Want to record the prompt and LLM settings for different runs in my DB. However, found promptflow didn't support any hooks in LLM node to retrieve the input before running or method to retrieve complete prompt after running.

Describe the solution you'd like
A hook before running LLM node or a method to retrive the prompt after running

Describe alternatives you've considered
Make custom tool to connect LLM? or formulate prompt before input to LLM node. For this, i need to give up using those useful features such as variants.

Additional context
Add any other context or screenshots about the feature request here.

Start by reviewing the LLM node execution path and how its prompt and settings are assembled. Determine whether a pre-run hook or post-run method should expose the complete prompt and settings, then consider how the API must behave with variants and recording data for different runs.