Removing go mod replace for `collector/service` and `collector/otelcol`

[ptodev]

In the spirit of "a little copying is better than a little dependency."....

I will also make a similar change to Agent. However, in the Agent I think we will still need the "service" package to be replaced so that we can embed the OTel Collector's metrics in the Agent's /metrics endpoint.

[ptodev]

This copying is not "a little", but I think it's still better than the go mod replace 😄