Revert "fix: remove redundant collectionSync"

This reverts commit e547d85f98.

src/Socket/chats.ts

@@ -167,6 +167,40 @@ export const makeChatsSocket = (config: SocketConfig) => {
         })
     }
 
+    const collectionSync = async(collections: { name: WAPatchName, version: number }[]) => {
+        const result = await query({
+            tag: 'iq',
+            attrs: {
+                to: S_WHATSAPP_NET,
+                xmlns: 'w:sync:app:state',
+                type: 'set'
+            },
+            content: [
+                {
+                    tag: 'sync',
+                    attrs: { },
+                    content: collections.map(
+                        ({ name, version }) => ({
+                            tag: 'collection',
+                            attrs:  { name, version: version.toString(), return_snapshot: 'true' }
+                        })
+                    )
+                }
+            ]
+        })
+        const syncNode = getBinaryNodeChild(result, 'sync')
+        const collectionNodes = getBinaryNodeChildren(syncNode, 'collection')
+        return collectionNodes.reduce(
+            (dict, node) => {
+                const snapshotNode = getBinaryNodeChild(node, 'snapshot')
+                if(snapshotNode) {
+                    dict[node.attrs.name] = snapshotNode.content as Uint8Array
+                }
+                return dict
+            }, { } as { [P in WAPatchName]: Uint8Array }
+        )
+    }
+
     /**
      * fetch the profile picture of a user/group
      * type = "preview" for a low res picture