Add NT controlled framerate limiter (#2257)

Adds a method to lower the speed of a pipeline over NT, primarily to
reduce power consumption.

photon-lib/py/photonlibpy/networktables/NTTopicSet.py

@@ -47,6 +47,13 @@ class NTTopicSet:
 
         self.driverModeSubscriber.getTopic().publish().setDefault(False)
 
+        self.fpsLimitPublisher = self.subTable.getIntegerTopic("fpsLimit").publish()
+        self.fpsLimitSubscriber = self.subTable.getIntegerTopic(
+            "fpsLimitRequest"
+        ).subscribe(-1)
+
+        self.fpsLimitSubscriber.getTopic().publish().setDefault(-1)
+
         self.latencyMillisEntry = self.subTable.getDoubleTopic(
             "latencyMillis"
         ).publish()