[FeatureRequest] Enable Debug Logging for Functions

[vrdmr]

Related: Azure/azure-functions-host#6879

Describe the request: A clear and concise description.
Make sure we are doing the following things to enable logging:

• Allow functions to have logging.debug (or equivalent in the language) to be logged and sent to the customer.
• The plan currently is for the host to send the logging levels used for each function and default to the worker and the worker will try to apply basic levels of filtering, and making sure the filtering is minimalistic to reduce a chance of over filtering.
• Also look at the plan for throttling and batching of the logs in such a way that the gRPC channel doesn't get overloaded when we send debug logs.

FYI: @mhoeger @pragnagopa @fabiocav