Add some tests for NotebookTab (#5070)

* EmptyApplication: Add asserts to rest of getters (except for getSeventvAPI)

* Theme: make getTheme call getIApp()->getThemes() instead

this allows it to be used in tests
realistically this should be deprecated & users of it should just call
getIApp()->getThemes() directly

* Use getIApp() instead of getApp() in a few places

mocks/include/mocks/EmptyApplication.hpp

@@ -17,61 +17,90 @@ public:
 
     Theme *getThemes() override
     {
+        assert(
+            false &&
+            "EmptyApplication::getThemes was called without being initialized");
         return nullptr;
     }
 
     Fonts *getFonts() override
     {
+        assert(
+            false &&
+            "EmptyApplication::getFonts was called without being initialized");
         return nullptr;
     }
 
     IEmotes *getEmotes() override
     {
+        assert(
+            false &&
+            "EmptyApplication::getEmotes was called without being initialized");
         return nullptr;
     }
 
     AccountController *getAccounts() override
     {
+        assert(false && "EmptyApplication::getAccounts was called without "
+                        "being initialized");
         return nullptr;
     }
 
     HotkeyController *getHotkeys() override
     {
+        assert(false && "EmptyApplication::getHotkeys was called without being "
+                        "initialized");
         return nullptr;
     }
 
     WindowManager *getWindows() override
     {
+        assert(false && "EmptyApplication::getWindows was called without being "
+                        "initialized");
         return nullptr;
     }
 
     Toasts *getToasts() override
     {
+        assert(
+            false &&
+            "EmptyApplication::getToasts was called without being initialized");
         return nullptr;
     }
 
     CrashHandler *getCrashHandler() override
     {
+        assert(false && "EmptyApplication::getCrashHandler was called without "
+                        "being initialized");
         return nullptr;
     }
 
     CommandController *getCommands() override
     {
+        assert(false && "EmptyApplication::getCommands was called without "
+                        "being initialized");
         return nullptr;
     }
 
     NotificationController *getNotifications() override
     {
+        assert(false && "EmptyApplication::getNotifications was called without "
+                        "being initialized");
         return nullptr;
     }
 
     HighlightController *getHighlights() override
     {
+        assert(false && "EmptyApplication::getHighlights was called without "
+                        "being initialized");
         return nullptr;
     }
 
     ITwitchIrcServer *getTwitch() override
     {
+        assert(
+            false &&
+            "EmptyApplication::getTwitch was called without being initialized");
         return nullptr;
     }
 
@@ -83,11 +112,15 @@ public:
 
     ChatterinoBadges *getChatterinoBadges() override
     {
+        assert(false && "EmptyApplication::getChatterinoBadges was called "
+                        "without being initialized");
         return nullptr;
     }
 
     FfzBadges *getFfzBadges() override
     {
+        assert(false && "EmptyApplication::getFfzBadges was called without "
+                        "being initialized");
         return nullptr;
     }
 
@@ -99,6 +132,8 @@ public:
 
     IUserDataController *getUserData() override
     {
+        assert(false && "EmptyApplication::getUserData was called without "
+                        "being initialized");
         return nullptr;
     }
 
@@ -110,11 +145,15 @@ public:
 
     ITwitchLiveController *getTwitchLiveController() override
     {
+        assert(false && "EmptyApplication::getTwitchLiveController was called "
+                        "without being initialized");
         return nullptr;
     }
 
     ImageUploader *getImageUploader() override
     {
+        assert(false && "EmptyApplication::getImageUploader was called without "
+                        "being initialized");
         return nullptr;
     }