Indexer updates backfill progress on no logs

[fbac]

Some changes are just style changes to make staticcheck linter happy.

[graphite-app]

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[macroscopeapp]

Update indexer backfill progress tracking to send UpdateProgress events instead of sleeping when no logs are found

The indexer now sends UpdateProgress events to track backfill progress when no logs are found, replacing the previous sleep mechanism. The changes include:

• Add UpdateProgressEventSignature(), IsUpdateProgressEvent(), and NewUpdateProgressLog() functions to log_handler.go for handling progress events
• Modify IndexLogs() function in log_handler.go to check for UpdateProgress events and update the block tracker
• Update backfill loop in rpc_log_streamer.go to send UpdateProgress events instead of sleeping when no logs are found
• Rename rpc_streamer package to rpcstreamer and update capitalization conventions across multiple files
• Add documentation comments following Go conventions

📍Where to Start

Start with the IndexLogs() function in log_handler.go to understand how UpdateProgress events are handled, then review the backfill loop in rpc_log_streamer.go to see how these events are generated.

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Macroscope summarized 0bd07fd.