feat(metrics): add Vector Throughput & health (via prometheus)

[lsampras]

Add a dashboard to monitor vector throughput usage and log loss.
The dashboard should show throughput for the following pipes

Throughput

1. stdout -> loki
2. stdout -> opensearch
3. kafka -> loki
4. Kafka -> transform -> opensearch
   These flows should include incoming events / outgoing events & dropped events as a time series chart

kafka source should contain consumer lag metrics as well

Health (this would be primarily powered by these metrics)

• CPU usage of vector
• Memory usage of vector
• buffer size
• errors happening in transforms
• utilization of each component

Ideally we can take most of the components from a openly available data source by modifying some components to make it geared towards our setup