K8SPG-833: watch envFrom secrets

[pooknull]

https://perconadev.atlassian.net/browse/K8SPG-833

DESCRIPTION

This PR fixes two issues:

1. When a secret is specified in envFrom but does not exist, the operator proceeds to create the cluster and fails. With these changes the operator will not create or update a cluster until the secret exists.
2. The operator does not reconcile when an envFrom secret is updated. Currently, it only watches secrets with the postgres-operator.crunchydata.com/cluster label. To call reconcile on envFrom secrets update, the field index was added that allows to list all clusters referencing a specific envFrom secret. Using this index, the new watchEnvFromSecrets function will call reconcile for clusters that depend on those secrets

There are no unit tests for this change, because it is difficult to test watch functions. All related tests were previously removed for this reason

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?

[JNKPercona]

Test Name	Result	Time
backup-enable-disable	passed	00:07:48
custom-extensions	passed	00:14:10
custom-tls	passed	00:05:42
database-init-sql	passed	00:03:31
demand-backup	passed	00:22:55
finalizers	passed	00:03:49
init-deploy	passed	00:03:04
monitoring	passed	00:07:52
monitoring-pmm3	passed	00:08:13
one-pod	passed	00:05:37
operator-self-healing	passed	00:08:14
pgvector-extension	passed	00:02:45
pitr	passed	00:11:34
scaling	passed	00:04:54
scheduled-backup	passed	00:27:39
self-healing	passed	00:09:23
sidecars	passed	00:02:35
start-from-backup	passed	00:11:40
tablespaces	passed	00:06:54
telemetry-transfer	passed	00:03:25
upgrade-consistency	passed	00:08:23
upgrade-minor	passed	00:06:02
users	passed	00:04:27
We run 23 out of 23		03:10:51

commit: 95e01dc
image: perconalab/percona-postgresql-operator:PR-1306-95e01dc5c