Best practice for developers control over which kernel functions get advertised to the LLM

[markwallace-microsoft]

Purpose of this task is to provide some guidance and samples for developers on how control which kernel functions get advertised to the LLM

Some options

1. Use the tool behaviour which allows the developer specify which functions from the kernel to use.
2. Provide an option when plugins/functions are registered to mark them as "not for LLM" e.g. if I have functions I only expected to be called when rendering prompts.