Test and verify pre-defined scenarios supported by opentelemetry-demo

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The opentelemetry-demo supports a series of pre-defined scenarios that can be enabled by following https://opentelemetry.io/docs/demo/feature-flags/.

To demonstrate the OpenTelemetry support by Instana, we should go through all the existing scenarios to test and verify if that can be supported by Instana. This can be a baseline of test cases for Instana OpenTelemetry support.