fix(limits): Read the consumer group and topic from the ingest-limits config

[periklis]

What this PR does / why we need it:
This pull request enables a separate configuration of the topic and consumer-group for the ingest-limits service. This enables to separate consumers from other components like partition-ingesters.

Which issue(s) this PR fixes:
Fixes #

Special notes for your reviewer:

Checklist

• Reviewed the CONTRIBUTING.md guide (required)
• Documentation added
• Tests updated
• Title matches the required conventional commits format, see here
  • Note that Promtail is considered to be feature complete, and future development for logs collection will be in Grafana Alloy. As such, feat PRs are unlikely to be accepted unless a case can be made for the feature actually being a bug fix to existing behavior.
• Changes that require user attention or interaction to upgrade are documented in docs/sources/setup/upgrade/_index.md
• If the change is deprecating or removing a configuration option, update the deprecated-config.yaml and deleted-config.yaml files respectively in the tools/deprecated-config-checker directory. Example PR

[github-actions]

💻 Deploy preview deleted.

[grobinson-grafana]

Looks good but I think you also need to remove this function:

// MetadataTopic returns the metadata topic name for the given topic.
func MetadataTopic(topic string) string {
	return topic + ".metadata"
}

and update its usage in different places like the stream generator.

[grobinson-grafana]

Nice!