[monitor - exporter] Add optional metrics/measurement param to `track_event`

[lewism77]

Is your feature request related to a problem? Please describe.
Currently it's not possible to add customMetrics/measurements to a custom event in App Insights. This is possible with other SDKs (e.g. .NET - telemetryclient.trackevent)

Describe the solution you'd like
Adding an optional parameter to track_event for the metrics would bring it in line with other SDKs.

Describe alternatives you've considered
I have looked at TrackMetric but specifically I want to add metrics to custom events (as I could in the .NET SDK). As a temporary workaround I'm converting the values to strings and adding it to the customDimensions.

Additional context
I was redirected to this repo's issues page from this repo: https://github.com/microsoft/ApplicationInsights-Python

Any workarounds for this would be welcome also.

[github-actions]

Thanks for the feedback! We are routing this to the appropriate team for follow-up. cc @AzmonActionG @azmonALERTS @AzMonEssential @AzmonLogA @dadunl @sameergMS.