EVM/Rollup nodes: identify traces origin

What

This MR adds service namespaces and instance identifiers for the rollup node and the EVM node.

Closes L2-70

Why

This allows to identify which node produced a given span. This can be useful for opentelemetry collectors that collect traces from different services (multiple rollup nodes and multiple EVM nodes).

How

• The namespace is static (rollup_node for rollup nodes and evm_node for EVM nodes) which allows to identify the kind of service for the span
• The instance id can be:
  • User provided in the configuration (in opentelemetry.instance_id)
  • Otherwise it is generated and stored in the data dir in <data_dir>/telemetry_id so that the same id is used for all runs of the same node.