Add Support for Azure WAL-G Backups (#1537)

This commit adds support for using an Azure storage account as a backup
location.

It uses the existing GCS functionality as a reference for what to do,
and follows the example set by GCS as closely as possible.

The decision to name the cloud provider key "aws_or_gcp" is unfortunate
while adding support for Azure, but I have left it alone to allow for
this changeset to be backwards compatible.

manifests/configmap.yaml

@@ -129,6 +129,7 @@ data:
   # team_api_role_configuration: "log_statement:all"
   # teams_api_url: http://fake-teams-api.default.svc.cluster.local
   # toleration: ""
+  # wal_az_storage_account: ""
   # wal_gs_bucket: ""
   # wal_s3_bucket: ""
   watched_namespace: "*"  # listen to all namespaces

manifests/operatorconfiguration.crd.yaml

@@ -384,6 +384,8 @@ spec:
                     type: string
                   log_s3_bucket:
                     type: string
+                  wal_az_storage_account:
+                    type: string
                   wal_gs_bucket:
                     type: string
                   wal_s3_bucket:

manifests/postgresql-operator-default-configuration.yaml

@@ -121,6 +121,7 @@ configuration:
     # gcp_credentials: ""
     # kube_iam_role: ""
     # log_s3_bucket: ""
+    # wal_az_storage_account: ""
     # wal_gs_bucket: ""
     # wal_s3_bucket: ""
   logical_backup: