Rollup-node: Improve Etherlink block tracing

What

This MR improves the tracing of Etherlink block processing in the rollup node. It introduces OpenTelemetry traces for block evaluation and removes the old, less precise event-based logging.

Why

The previous event-based logging for Etherlink block processing was not detailed enough for effective performance analysis. By introducing OpenTelemetry traces, we gain more granular and structured data, which allows for better observability and easier identification of performance bottlenecks. This change also simplifies the codebase by removing redundant logging mechanisms.

How

• The kernel_tracing function is modified to create a new OpenTelemetry span for each evaluated Etherlink block. This span is linked to the parent eval_block span and includes the block number as an attribute.
• The old etherlink_blocks_processed event and its associated logic are removed from the rollup node daemon.
• A new event eval_etherlink_block is added to log the block number and evaluation time.