Draft: Adding log messages for Perf Testing

We need to run perf tests on indexer queue in order to collect performance numbers like throughput of messages, number of messages being sent to dead letter queue, etc. This MR adds log messages for the same.

Since indexer queue is an azure function, it cannot be easily run locally. The testing of these changes need to be done in a test environment, and hence this MR is in draft state until then.