volume stack spec udpates to external (#754)

Author: blewisCycle

components/schemas/infrastructure/external-volumes/ExternalVolumeEvents.yml

@@ -15,6 +15,10 @@ properties:
   deleted:
     description: The timestamp of when the attached volume was deleted.
     $ref: "../../DateTime.yml"
+  last_verified:
+    $ref: "../../DateTime.yml"
+    description: >
+      Timestamp of the last successful verification event for this volume.
   last_sync:
     $ref: "../../DateTime.yml"
     description: >

stackspec/schema/StackSpecContainerVolume.yml

@@ -28,21 +28,13 @@ properties:
   external:
     anyOf:
       - type: object
-        required:
-          - mode
         properties:
           id:
             oneOf:
-              - $ref: ../../components/schemas/ID.yml
+              - $ref: ../../components/schemas/HybridIdentifier.yml
               - $ref: StackVariable.yml
               - type: "null"
             description: The ID of the external volume.
-          mode:
-            oneOf:
-              - type: string
-                description: The attachment mode for the external volume.
-                enum: [instance, host]
-              - $ref: StackVariable.yml
       - $ref: StackVariable.yml
       - type: "null"
   destination: