AP featured collectionの修正 / Collection Activityの対応 / typeの修正など (#5460)

* resolver type / fix updateFeatured

* type ApObject

* fix strange type

* AP Activity

* Collection Activityが失敗したらとりあえず無視

src/prelude/array.ts

@@ -120,3 +120,11 @@ export function cumulativeSum(xs: number[]): number[] {
 export function fromEntries(xs: [string, any][]): { [x: string]: any; } {
 	return xs.reduce((obj, [k, v]) => Object.assign(obj, { [k]: v }), {} as { [x: string]: any; });
 }
+
+export function toArray<T>(x: T | T[] | undefined): T[] {
+	return Array.isArray(x) ? x : x != null ? [x] : [];
+}
+
+export function toSingle<T>(x: T | T[] | undefined): T | undefined {
+	return Array.isArray(x) ? x[0] : x;
+}