Bootstrapped databases with best practice role setup (#843)

* PreparedDatabases with default role setup

* merge changes from master

* include preparedDatabases spec check when syncing databases

* create a default preparedDB if not specified

* add more default privileges for schemas

* use empty brackets block for undefined objects

* cover more default privilege scenarios and always define admin role

* add DefaultUsers flag

* support extensions and defaultUsers for preparedDatabases

* remove exact version in deployment manifest

* enable CRD validation for new field

* update generated code

* reflect code review

* fix typo in SQL command

* add documentation for preparedDatabases feature + minor changes

* some datname should stay

* add unit tests

* reflect some feedback

* init users for preparedDatabases also on update

* only change DB default privileges on creation

* add one more section in user docs

* one more sentence

charts/postgres-operator/crds/postgresqls.yaml

@@ -273,6 +273,26 @@ spec:
                   type: object
                   additionalProperties:
                     type: string
+            preparedDatabases:
+              type: object
+              additionalProperties:
+                type: object
+                properties:
+                  defaultUsers:
+                    type: boolean
+                  extensions:
+                    type: object
+                    additionalProperties:
+                      type: string
+                  schemas:
+                    type: object
+                    additionalProperties:
+                      type: object
+                      properties:
+                        defaultUsers:
+                          type: boolean
+                        defaultRoles:
+                          type: boolean
             replicaLoadBalancer:  # deprecated
               type: boolean
             resources: