feat(bunotel): Ability to override span names

[NathanBaulch]

Bun OTEL spans would be much more informative in APM tools if their name included the primary table being queried. This could be added easily enough, however it might be nice to follow the convention used in other popular middlewares like otelhttp by adding a WithSpanNameFormatter option.

This PR allows me to add the primary query table to span names like so:

bunotel.NewQueryHook(bunotel.WithSpanNameFormatter(func(event *bun.QueryEvent) string {
	name := event.Operation()
	if event.IQuery != nil {
		if tableName := event.IQuery.GetTableName(); tableName != "" {
			name += " " + tableName
		}
	}
	return name
}))