K8SPG-648: fix patroni-version-check behaviour on startup

[pooknull]

https://perconadev.atlassian.net/browse/K8SPG-648

DESCRIPTION

Problem:
patroni-version-check is created multiple times on startup, when it should be created only once.

Cause:
Instance pods don't have imageID's on startup. Operator can't find the previous imageID in the empty slice of pod's imageID's and creates new version check.

Solution:
Add a check for an empty imageID slice.

This PR adds the following resources to the patroni-version-check pod:

limits:
    cpu: 100m
    memory: 64Mi
requests:
    cpu: 50m
    memory: 32Mi

Also, the pgv2.percona.com/custom-patroni-version annotation is added to disable patroni-version-check by overriding the patroni version with a custom value.

kind: PerconaPGCluster
metadata:
  name: cluster1
  annotations:
    pgv2.percona.com/custom-patroni-version: "4"

CHECKLIST

Jira

• Is the Jira ticket created and referenced properly?
• Does the Jira ticket have the proper statuses for documentation (Needs Doc) and QA (Needs QA)?
• Does the Jira ticket link to the proper milestone (Fix Version field)?

Tests

• Is an E2E test/test case added for the new feature/change?
• Are unit tests added where appropriate?

Config/Logging/Testability

• Are all needed new/changed options added to default YAML files?
• Are all needed new/changed options added to the Helm Chart?
• Did we add proper logging messages for operator actions?
• Did we ensure compatibility with the previous version or cluster upgrade process?
• Does the change support oldest and newest supported PG version?
• Does the change support oldest and newest supported Kubernetes version?

[nmarukovich]

why we can decrease it?

[pooknull]

We don't need such a big sleep. Our reconcile loop should not take more than 1 minute