Instrument ClickHouse-Go for Database Level Tracing

[taitelee]

Problem

The trace currently ends when the Go code calls the database. We can see "how long" the query took from the Go side, but we can't see what ClickHouse was doing internally or if the query was delayed by ClickHouse's own internal execution plan.

Proposed Solution

Leverage the native OpenTelemetry support in clickhouse-go/v2.

• Pass the context.Context (which now contains the Trace ID) into every Exec, Query, or Prepare call.
• ClickHouse Side: Ensure the ClickHouse server is configured to accept OpenTelemetry headers (available in version 23.x+).
• Benefit: SigNoz will show a dedicated span for the database execution, including the actual SQL query performed.

Alternatives Considered

None

Additional Context

None