Given that external_data_source.js fails very rarely as we add more test jobs, it would be helpful to add some more logging so that we can quickly identify the same failure pattern when there's thread resource shortage.

We have testSimpleAggregationsOverExternalDataSource() function in external_data_source.js and this function executes many test cases. We can add progress logging for each test case.

And we can add INFO-level logging to writeToPipeObjectsAsync shell function. This function is called in the context of tests and so it's safe to add INFO-level logging.

Other than this, we should add requires_external_data_source exclusion tag to newly failing build variants which are enterprise-rhel80-fixed-service-executor-64-bit and linux-x86-dynamic-grpc-suggested just like this commit.