Switches AnalogInputs and AnalogTriggers to Handles (#117)

Results in a breaking change to AnalogTrigger int constructor. If a user wants
multiple AnalogTriggers, they must use the AnalogInput constructor.

hal/lib/athena/AnalogInternal.cpp

@@ -15,6 +15,11 @@ namespace hal {
 priority_recursive_mutex analogRegisterWindowMutex;
 tAI* analogInputSystem = nullptr;
 tAO* analogOutputSystem = nullptr;
+
+IndexedHandleResource<HalAnalogInputHandle, hal::AnalogPort, kAnalogInputPins,
+                      HalHandleEnum::AnalogInput>
+    analogInputHandles;
+
 static uint32_t analogNumChannelsToActivate = 0;
 
 bool analogSystemInitialized = false;