test(core): chat with collection & tags (#11388)

### TL:DR

* AI chat with collection E2E
* AI chat with tag E2E

> Close BS-3007

packages/frontend/core/src/modules/explorer/views/nodes/collection/operations.tsx

@@ -118,6 +118,7 @@ export const useExplorerCollectionNodeOperations = (
         view: (
           <IconButton
             size="16"
+            data-testid="collection-add-doc-button"
             onClick={handleAddDocToCollection}
             tooltip={t[
               'com.affine.rootAppSidebar.explorer.collection-add-tooltip'

packages/frontend/core/src/modules/explorer/views/nodes/tag/operations.tsx

@@ -91,6 +91,7 @@ export const useExplorerTagNodeOperations = (
           <IconButton
             size="16"
             onClick={handleNewDoc}
+            data-testid="tag-add-doc-button"
             tooltip={t['com.affine.rootAppSidebar.explorer.tag-add-tooltip']()}
           >
             <PlusIcon />

packages/frontend/core/src/modules/explorer/views/sections/tags/index.tsx

@@ -43,6 +43,7 @@ export const ExplorerTags = () => {
   return (
     <CollapsibleSection
       name="tags"
+      testId="explorer-tags"
       headerClassName={styles.draggedOverHighlight}
       title={t['com.affine.rootAppSidebar.tags']()}
       actions={