feat: add mod update check tasks

Those tasks take a list of mods and check on the mod providers for
updates. They assume that the mods have metadata already.

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

launcher/modplatform/CheckUpdateTask.h

@@ -0,0 +1,51 @@
+#pragma once
+
+#include "minecraft/mod/Mod.h"
+#include "modplatform/ModAPI.h"
+#include "modplatform/ModIndex.h"
+#include "tasks/Task.h"
+
+class ModDownloadTask;
+class ModFolderModel;
+
+class CheckUpdateTask : public Task {
+    Q_OBJECT
+
+   public:
+    CheckUpdateTask(std::list<Mod>& mods, std::list<Version>& mcVersions, ModAPI::ModLoaderTypes loaders, std::shared_ptr<ModFolderModel> mods_folder)
+        : m_mods(mods), m_game_versions(mcVersions), m_loaders(loaders), m_mods_folder(mods_folder) {};
+
+    struct UpdatableMod {
+        QString name;
+        QString old_hash;
+        QString old_version;
+        QString new_version;
+        QString changelog;
+        ModPlatform::Provider provider;
+        ModDownloadTask* download;
+
+       public:
+        UpdatableMod(QString name, QString old_h, QString old_v, QString new_v, QString changelog, ModPlatform::Provider p, ModDownloadTask* t)
+            : name(name), old_hash(old_h), old_version(old_v), new_version(new_v), changelog(changelog), provider(p), download(t)
+        {}
+    };
+
+    auto getUpdatable() -> std::vector<UpdatableMod>&& { return std::move(m_updatable); }
+
+   public slots:
+    bool abort() override = 0;
+
+   protected slots:
+    void executeTask() override = 0;
+
+   signals:
+    void checkFailed(Mod failed, QString reason, QUrl recover_url = {});
+
+   protected:
+    std::list<Mod>& m_mods;
+    std::list<Version>& m_game_versions;
+    ModAPI::ModLoaderTypes m_loaders;
+    std::shared_ptr<ModFolderModel> m_mods_folder;
+
+    std::vector<UpdatableMod> m_updatable;
+};