fix(esm): improve ESM compatibility and modernize package configuration

ts/index.ts

@@ -1,4 +1,33 @@
 export * from './smartspawn.classes.threadsimple.js';
 export * from './smartspawn.wrap.js';
 
-export * from 'threads';
+import { createRequire } from 'module';
+
+const require = createRequire(import.meta.url);
+
+export interface IThreadsModule {
+  BlobWorker: new (...args: unknown[]) => unknown;
+  DefaultSerializer: unknown;
+  Pool: unknown;
+  Thread: {
+    terminate: (threadArg: unknown) => Promise<void> | void;
+    events?: (threadArg: unknown) => unknown;
+  };
+  Transfer: (payloadArg: unknown, transferablesArg?: Transferable[]) => unknown;
+  Worker: new (workerPathArg: string | URL, optionsArg?: unknown) => unknown;
+  registerSerializer: (serializerArg: unknown) => void;
+  spawn: <T = unknown>(workerArg: unknown, optionsArg?: unknown) => Promise<T>;
+}
+
+const threads = require('threads') as IThreadsModule;
+
+export const {
+  BlobWorker,
+  DefaultSerializer,
+  Pool,
+  Thread,
+  Transfer,
+  Worker,
+  registerSerializer,
+  spawn,
+} = threads;