[BFCL] Relocate Formatting Instructions and Function Documentation to System Prompt

[HuanzhiMao]

Previously, formatting instructions and function documentation were included in the user prompt when interacting with models in prompting mode. However, these details are better suited for the system prompt, where they can more effectively guide the model's behaviour. This PR updates the model prompting process by moving the formatting instructions and function documentation to the system prompt, ensuring they are appropriately positioned for optimal model performance.

This will affect the leaderboard score.

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Also in this PR:

1. Update the model handlers to record the processed prompt/message and tools (if FC mode) in the result file when inference. This helps to identify if there are any issues with the pre-processing phase.
2. Fix 6 dataset issues: irrelevance_49, live_irrelevance_157-18-1, live_simple_79-40-0, live_parallel_0-0-0, live_parallel_4-1-0, live_parallel_5-2-0

[CharlieJCJ]

Tested on Gorilla openfunctions and GPT models, both prompt and FC models, LGTM.

Logging of processed_message will add a lot of debuggability for adding new model handlers.