feat(RD): add texture pack downloader

This extends the resource pack downloader, with the custom behavior of
filtering the versions that shows up, to those <= 1.6. As always, Flame
is funky and requires a bit more workarounds than average.

This will also get a nice improvement when the Version parsing and
comparison PR gets merged! :D

Signed-off-by: flow <flowlnlnln@gmail.com>

launcher/ui/pages/modplatform/ResourcePackPage.h

@@ -39,7 +39,7 @@ class ResourcePackResourcePage : public ResourcePage {
     [[nodiscard]] QMap<QString, QString> urlHandlers() const override;
 
    protected:
-    ResourcePackResourcePage(ResourcePackDownloadDialog* dialog, BaseInstance& instance);
+    ResourcePackResourcePage(ResourceDownloadDialog* dialog, BaseInstance& instance);
 
    protected slots:
     void triggerSearch() override;