refactor(Application.h): reduce include chain

Include only what's absolutely necessary to reduce headers pulled into a
translation unit. If you need access to
instance's from `APPLICATION` include `BaseInstance.h` separately

Signed-off-by: Rachel Powers <508861+Ryex@users.noreply.github.com>

launcher/include/base.pch.hpp

@@ -3,6 +3,7 @@
 #define PRISM_PRECOMPILED_BASE_HEADERS_H
 
 #include <algorithm>
+#include <cstddef>
 #include <functional>
 #include <memory>
 #include <optional>

launcher/include/qtcore.pch.hpp

@@ -5,9 +5,15 @@
 #include <QEvent>
 #include <QMetaType>
 #include <QObject>
+
+#include <QPointer>
+#include <QSharedPointer>
+
 #include <QVariant>
+#include <QVariantMap>
 
 #include <QDebug>
+#include <QLoggingCategory>
 
 #include <QCoreApplication>