Adjust 2k environment config (Webservice, Sidekiq)

What does this MR do?

MR switches 2k Cloud Native Hybrid setups to use 4 worker webservice pods instead of 2. This make it consistent with all other Ref Arch sizes as well as allowing more room for shared memory.

Sidekiq workers are also increased from 2 to 4 to be more in line with the other architectures and give more headroom. (Requires a small change to the Reference Architecture).

Also fixes Pod count selection logic, removes some postgres output when not in a cluster and assign the correct postgres role when non HA.

Related issues

Relates gitlab-org/quality/reference-architectures#146 (closed)

Author's checklist

When ready for review, the Author applies the workflowready for review label and mention @gl-quality/get-maintainers:

• Merge request:
  • Corresponding Issue raised and reviewed by the GET maintainers team.
  • Merge Request Title and Description are up-to-date, accurate, and descriptive
  • MR targeting the appropriate branch
  • MR has a green pipeline
  • MR has no new security alerts in the widget from the Secret Detection and IaC Scan (SAST) jobs.
• Code:
  • Check the area changed works as expected. Consider testing it in different environment sizes (1k,3k,10k,etc.).
  • Documentation created/updated in the same MR.
  • If this MR adds an optional configuration - check that all permutations continue to work.
  • For Terraform changes: set up a previous version environment, then run a terraform plan with your new changes and ensure nothing will be destroyed. If anything will be destroyed and this can't be avoided please add a comment to the current MR.
• Create any follow-up issue(s) to support the new feature across other supported cloud providers or advanced configurations. Create 1 issue for each provider/configuration. Contact the Quality Enablement team if unsure.