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/common/Common.hpp

@@ -1,9 +1,5 @@
 #pragma once
 
-#include "common/Aliases.hpp"
-#include "common/Outcome.hpp"
-#include "common/ProviderId.hpp"
-
 #include <boost/optional.hpp>
 #include <boost/preprocessor.hpp>
 #include <QString>
@@ -20,11 +16,6 @@ enum class HighlightState {
     NewMessage,
 };
 
-inline QString qS(const std::string &string)
-{
-    return QString::fromStdString(string);
-}
-
 const Qt::KeyboardModifiers showSplitOverlayModifiers =
     Qt::ControlModifier | Qt::AltModifier;
 const Qt::KeyboardModifiers showAddSplitRegions =