fix(typescript): tighten TypeScript typings and modernize project tooling configuration

ts/smartpromise.classes.cumulativedeferred.ts

@@ -1,8 +1,8 @@
-import { defer } from "./smartpromise.classes.deferred.js";
+import { defer } from './smartpromise.classes.deferred.js';
 
 export class CumulativeDeferred {
-  private accumulatedPromises: Promise<any>[] = [];
-  private deferred = defer();
+  private accumulatedPromises: Promise<unknown>[] = [];
+  private deferred = defer<void>();
   public promise = this.deferred.promise;
 
   constructor() {
@@ -16,17 +16,16 @@ export class CumulativeDeferred {
   }
 
   public subDefer() {
-    const done = defer();
+    const done = defer<void>();
     this.addPromise(done.promise);
     return done;
   }
 
-  public addPromise(promiseArg: Promise<any>) {
+  public addPromise(promiseArg: Promise<unknown>): void {
     this.accumulatedPromises.push(promiseArg);
   }
 }
 
-
 export const cumulativeDefer = () => {
   return new CumulativeDeferred();
-}
+};