refactor: move mod tasks to their own subfolder

Makes the launcher/minecraft/mod/ folder a little more organized.

launcher/minecraft/mod/tasks/LocalModUpdateTask.cpp

@@ -0,0 +1,31 @@
+#include "LocalModUpdateTask.h"
+
+#include <toml.h>
+
+#include "FileSystem.h"
+#include "modplatform/packwiz/Packwiz.h"
+
+LocalModUpdateTask::LocalModUpdateTask(QDir index_dir, ModPlatform::IndexedPack& mod, ModPlatform::IndexedVersion& mod_version)
+    : m_index_dir(index_dir), m_mod(mod), m_mod_version(mod_version)
+{
+    // Ensure a '.index' folder exists in the mods folder, and create it if it does not
+    if (!FS::ensureFolderPathExists(index_dir.path())) {
+        emitFailed(QString("Unable to create index for mod %1!").arg(m_mod.name));
+    }
+}
+
+void LocalModUpdateTask::executeTask()
+{
+    setStatus(tr("Updating index for mod:\n%1").arg(m_mod.name));
+
+    auto pw_mod = Packwiz::createModFormat(m_index_dir, m_mod, m_mod_version);
+    Packwiz::updateModIndex(m_index_dir, pw_mod);
+
+    emitSucceeded();
+}
+
+bool LocalModUpdateTask::abort()
+{
+    emitAborted();
+    return true;
+}