Allow configuration of patroni's replication mode (#869)

* Add patroni parameters for `synchronous_mode`

* Update complete-postgres-manifest.yaml, removed quotation marks

* Update k8sres_test.go, adjust result for `Patroni configured`

* Update k8sres_test.go, adjust result for `Patroni configured`

* Update complete-postgres-manifest.yaml, set synchronous mode to false in this example

* Update pkg/cluster/k8sres.go

Does the same but is shorter. So we fix that it if you like.

Co-Authored-By: Felix Kunde <felix-kunde@gmx.de>

* Update docs/reference/cluster_manifest.md

Co-Authored-By: Felix Kunde <felix-kunde@gmx.de>

* Add patroni's `synchronous_mode_strict`

* Extend `TestGenerateSpiloConfig` with `SynchronousModeStrict`

Co-authored-by: Felix Kunde <felix-kunde@gmx.de>

manifests/complete-postgres-manifest.yaml

@@ -67,6 +67,8 @@ spec:
     ttl: 30
     loop_wait: &loop_wait 10
     retry_timeout: 10
+    synchronous_mode: false
+    synchronous_mode_strict: false
     maximum_lag_on_failover: 33554432
 
 # restore a Postgres DB with point-in-time-recovery

manifests/postgresql.crd.yaml

@@ -184,6 +184,10 @@ spec:
                   type: integer
                 maximum_lag_on_failover:
                   type: integer
+                synchronous_mode:
+                  type: boolean
+                synchronous_mode_strict:
+                  type: boolean
             podAnnotations:
               type: object
               additionalProperties: