Allow managing collection accounts (#37812)

app/javascript/mastodon/api/collections.ts

@@ -11,6 +11,7 @@ import type {
   ApiCreateCollectionPayload,
   ApiUpdateCollectionPayload,
   ApiCollectionsJSON,
+  WrappedCollectionAccountItem,
 } from '../api_types/collections';
 
 export const apiCreateCollection = (collection: ApiCreateCollectionPayload) =>
@@ -37,3 +38,14 @@ export const apiGetAccountCollections = (accountId: string) =>
   apiRequestGet<ApiCollectionsJSON>(
     `v1_alpha/accounts/${accountId}/collections`,
   );
+
+export const apiAddCollectionItem = (collectionId: string, accountId: string) =>
+  apiRequestPost<WrappedCollectionAccountItem>(
+    `v1_alpha/collections/${collectionId}/items`,
+    { account_id: accountId },
+  );
+
+export const apiRemoveCollectionItem = (collectionId: string, itemId: string) =>
+  apiRequestDelete<WrappedCollectionAccountItem>(
+    `v1_alpha/collections/${collectionId}/items/${itemId}`,
+  );