Each otelcol component should be able to override its debug metrics level

[ptodev]

Request

#791 sets all otelcol component's debug metrics level to "detailed". It would be nice if we can override this on a per-component basis. For example, the debug_metrics block could have an additional parameter called "level" which can be set to the different levels described in configtelemetry.go.

Use case

This is mostly useful so that folks can turn off the grpc metrics completely.