[exporter/dynatrace] Ensure Validate implementation does the right thing

[codeboten]

This change in the collector core added a Validate method to QueueSettings which caused ambiguity with the ExporterSettings’ Validate method. As a result, I’ve added a Validate method to this exporter and an issue to ensure it was doing the right thing.

Here is an example of the validate method for the OTLP exporter calling the QueueSettings’ Validate

open-telemetry/opentelemetry-collector@48c402d#diff-a56037437974f775001642d59880ac9dd0c14cab137576b4f4a6df01a230a84cR39-R42

Originally posted by @codeboten in #7779 (comment)

[jpkrohling]

cc @dyladan @arminru

[pichlermarc]

I would like to pick this one up :)

[jpkrohling]

It's yours.