Give activities names and log when entering and exiting them (#92)

## Summary

* Give activities name and log when entering and exiting them
* Clearer logs when attempting to debug, knowing where users are coming
from/going to helps

src/activities/Activity.h

@@ -1,19 +1,22 @@
 #pragma once
 #include <InputManager.h>
 
+#include <utility>
+
 class GfxRenderer;
 
 class Activity {
  protected:
+  std::string name;
   GfxRenderer& renderer;
   InputManager& inputManager;
 
  public:
-  explicit Activity(GfxRenderer& renderer, InputManager& inputManager)
-      : renderer(renderer), inputManager(inputManager) {}
+  explicit Activity(std::string name, GfxRenderer& renderer, InputManager& inputManager)
+      : name(std::move(name)), renderer(renderer), inputManager(inputManager) {}
   virtual ~Activity() = default;
-  virtual void onEnter() {}
-  virtual void onExit() {}
+  virtual void onEnter() { Serial.printf("[%lu] [ACT] Entering activity: %s\n", millis(), name.c_str()); }
+  virtual void onExit() { Serial.printf("[%lu] [ACT] Exiting activity: %s\n", millis(), name.c_str()); }
   virtual void loop() {}
   virtual bool skipLoopDelay() { return false; }
 };