feat(extension): expose request mutation methods on task.meta.req (#1538)

pkg/download/testdata/extensions/basic/index.js

@@ -1,7 +1,10 @@
 gopeed.events.onResolve(async function (ctx) {
-    await ctx.req.setLabels({ replaced: "true", removed: "true" });
-    await ctx.req.putLabel("modified", "true");
-    await ctx.req.delLabel("removed");
+    for (const method of ['setUrl', 'setLabels', 'putLabel', 'delLabel', 'setMethod', 'putHeader', 'setTrackers']) {
+        if (typeof ctx.req[method] !== 'undefined') throw new Error(`onResolve exposes ${method}`);
+    }
+    ctx.req.labels = { replaced: "true", removed: "true" };
+    ctx.req.labels.modified = "true";
+    delete ctx.req.labels.removed;
     ctx.res = {
         name: "test",
         files: Array(2).fill(true).map((_, i) => ({