Add node messages to node get (#836)

This exposes the node commands that have yet to be processed by the node.  Example use case:  The SDK can now ask "has this node installed my SSH key"

src/pytypes/onefuzztypes/models.py

@@ -557,6 +557,29 @@ class NodeHeartbeatEntry(BaseModel):
     data: List[Dict[str, HeartbeatType]]
 
 
+class StopNodeCommand(BaseModel):
+    pass
+
+
+class StopTaskNodeCommand(BaseModel):
+    task_id: UUID
+
+
+class NodeCommandAddSshKey(BaseModel):
+    public_key: str
+
+
+class NodeCommand(EnumModel):
+    stop: Optional[StopNodeCommand]
+    stop_task: Optional[StopTaskNodeCommand]
+    add_ssh_key: Optional[NodeCommandAddSshKey]
+
+
+class NodeCommandEnvelope(BaseModel):
+    command: NodeCommand
+    message_id: str
+
+
 class Node(BaseModel):
     timestamp: Optional[datetime] = Field(alias="Timestamp")
     pool_name: PoolName
@@ -564,6 +587,7 @@ class Node(BaseModel):
     state: NodeState = Field(default=NodeState.init)
     scaleset_id: Optional[UUID] = None
     tasks: Optional[List[Tuple[UUID, NodeTaskState]]] = None
+    messages: Optional[List[NodeCommand]] = None
     heartbeat: Optional[datetime]
     version: str = Field(default="1.0.0")
     reimage_requested: bool = Field(default=False)
@@ -776,29 +800,6 @@ class NodeEventEnvelope(BaseModel):
     event: NodeEventShim
 
 
-class StopNodeCommand(BaseModel):
-    pass
-
-
-class StopTaskNodeCommand(BaseModel):
-    task_id: UUID
-
-
-class NodeCommandAddSshKey(BaseModel):
-    public_key: str
-
-
-class NodeCommand(EnumModel):
-    stop: Optional[StopNodeCommand]
-    stop_task: Optional[StopTaskNodeCommand]
-    add_ssh_key: Optional[NodeCommandAddSshKey]
-
-
-class NodeCommandEnvelope(BaseModel):
-    command: NodeCommand
-    message_id: str
-
-
 class TaskEvent(BaseModel):
     timestamp: Optional[datetime] = Field(alias="Timestamp")
     task_id: UUID