feat: log ingestion policy when log_push_request is set

[salvacorts]

What this PR does / why we need it:

With log_push_request we can log all the streams a customer is pushing. This is useful to debug which streams are discarded later on. To debug logs dropped due to blocked policies on the operator end, we are resolving a printing the policy when log_push_request is enabled.

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

[trevorwhitney]

lgtm