Keep multi requests for smartcam devices after a timeout (#1802)

Smartcam devices do not support sending individual requests, but respond always with `PROTOCOL_FORMAT_ERROR
(-40210)`.

This commit forces them to always use the multi-request format for requests even after receiving an error where we would otherwise fallback to individual requests.

kasa/protocols/smartprotocol.py

@@ -103,6 +103,8 @@ class SmartProtocol(BaseProtocol):
 
     BACKOFF_SECONDS_AFTER_TIMEOUT = 1
     DEFAULT_MULTI_REQUEST_BATCH_SIZE = 5
+    # True if the device rejects single requests, so batching is never disabled.
+    REQUIRES_MULTIREQUESTS = False
 
     def __init__(
         self,
@@ -248,6 +250,8 @@ class SmartProtocol(BaseProtocol):
             try:
                 response_step = await self._transport.send(smart_request)
             except TimeoutError as ex:
+                if self.REQUIRES_MULTIREQUESTS:
+                    raise
                 # P300 does not respond to some batched requests (e.g. both child
                 # list requests together) so disable batching. Batch size is never
                 # 1 here as that case sends single requests above.
@@ -278,6 +282,7 @@ class SmartProtocol(BaseProtocol):
                         SmartErrorCode.INTERNAL_UNKNOWN_ERROR,
                     }
                     and self._multi_request_batch_size != 1
+                    and not self.REQUIRES_MULTIREQUESTS
                 ):
                     self._multi_request_batch_size = 1
                     raise _RetryableError(