refactor: move more tied logic to model and move logic to the resources

This moves the QSortFilterProxyModel to the resource model files,
acessible via a factory method, and moves the sorting and filtering to
the objects themselves, decoupling the code a bit.

This also adds a basic implementation of methods in the
ResourceFolderModel, simplifying the process of constructing a new model
from it.

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

launcher/minecraft/mod/ModFolderModel.h

@@ -91,15 +91,13 @@ public:
     /// Deletes all the selected mods
     bool deleteMods(const QModelIndexList &indexes);
 
-    void disableInteraction(bool disabled) { ResourceFolderModel::enableInteraction(!disabled); }
-
     /// Enable or disable listed mods
     bool setModStatus(const QModelIndexList &indexes, ModStatusAction action);
 
     bool isValid();
 
-    void startWatching();
-    void stopWatching();
+    bool startWatching() override;
+    bool stopWatching() override;
 
     QDir indexDir() { return { QString("%1/.index").arg(dir().absolutePath()) }; }