feat: Added banners, replace some modals with them

lib/libimhex/source/ui/banner.cpp

@@ -0,0 +1,18 @@
+#include <hex/ui/banner.hpp>
+#include <hex/helpers/auto_reset.hpp>
+
+namespace hex::impl {
+
+    [[nodiscard]] std::list<std::unique_ptr<BannerBase>> &BannerBase::getOpenBanners() {
+        static AutoReset<std::list<std::unique_ptr<BannerBase>>> openBanners;
+
+        return openBanners;
+    }
+
+    std::mutex& BannerBase::getMutex() {
+        static std::mutex mutex;
+
+        return mutex;
+    }
+
+}