Massage includes some more (#4294)

* Add `<functional>` include to QStringHash.hpp

This ensures the base `std::hash` template is declared before this
specialization

* Add missing includes to `src/providers/twitch/TwitchAccountManager.hpp`

* Move explicit HelixChatters constructor to the source file

* Remove unused includes & add used includes to NicknamesModel.hpp

* NicknamesModel.hpp: Remove `virtual` when `override` is used

* Add missing QStringHash include to TwitchEmotes.cpp

* Add missing includes to various files

* Print Qt version in cmake step

Technically unrelated, but I'm sneaking it in

* Add changelog entry

src/providers/seventv/eventapi/SeventvEventAPISubscription.cpp

@@ -1,8 +1,11 @@
 #include "providers/seventv/eventapi/SeventvEventAPISubscription.hpp"
 
+#include <QDebug>
 #include <QJsonDocument>
 #include <QJsonObject>
 
+#include <tuple>
+
 namespace {
 
 using namespace chatterino;