Expose Listener and Function host 4XX Errors to Function App operators

#### What problem would the feature you're requesting solve? Please describe.
Any 4xx errors raised by the Linux function host / listeners are not surfaced for a Function App operator to view.
Windows function apps surface these on a diagnostics pane called 'HTTP 4XX Errors' and I can see all-sorts of errors that were returned to consumers but didn't come from my application code. On Linux I cannot see these anywhere.

As a function developer there is a lot of useful information exposed to Windows function plans, not accessible to Linux that will help me operate my functions better.

#### Describe the solution you'd like
I would like all errors sent back to function consumers on a Linux Plan to be reported by the function in either Application Insights, Log Analytics, or on a HTTP 4XX Diagnostics pane like in Windows function apps.

#### Describe alternatives you've considered
Switching to a windows plan.

#### Additional context
##### Windows 4XX errors showing the exceptions returned to the consumer by the Windows worker / listeners.

No files, tests, or entry points are named in the issue. Start by tracing how Linux function-host and listener 4XX responses are handled and compare that path with Windows diagnostics. Done would mean defining and implementing a supported way for Function App operators to view these errors, with coverage for the chosen reporting destination.

Written by the indexing model from the issue text.