Remove Unnecessary Includes in Headers (#4275)

* refactor: remove unnecessary includes in headers

* fix: formatting

* chore: changelog

* fix: scrollbar

* fix: suggestions and old appbase remains

* fix: suggestion

* fix: missing Qt forward declarations

* fix: another qt include

* fix: includes for precompiled-headers=off

* Add missing `<memory>` includes

* Add missing `#pragma once`

* Fix tests

Co-authored-by: Rasmus Karlsson <rasmus.karlsson@pajlada.com>

src/messages/Image.cpp

@@ -3,6 +3,8 @@
 #include "Application.hpp"
 #include "common/Common.hpp"
 #include "common/NetworkRequest.hpp"
+#include "common/NetworkResult.hpp"
+#include "common/Outcome.hpp"
 #include "common/QLogging.hpp"
 #include "debug/AssertInGuiThread.hpp"
 #include "debug/Benchmark.hpp"
@@ -347,6 +349,11 @@ ImagePtr Image::getEmpty()
     return empty;
 }
 
+ImagePtr getEmptyImagePtr()
+{
+    return Image::getEmpty();
+}
+
 Image::Image()
     : empty_(true)
 {