refactor: update imports to use ES module syntax and improve test structure (#1350)

- Changed import statements across multiple files to use the .js extension for ES module compatibility.
- Refactored test files to utilize jest's unstable_mockModule for mocking core actions.
- Removed unnecessary spy instances in tests, replacing them with direct mocked function calls.
- Updated TypeScript configuration to target ES2022 and use NodeNext module resolution.
- Removed the tsconfig.spec.json file and adjusted the main tsconfig.json to exclude test files.

src/classes/statistics.ts

@@ -1,6 +1,6 @@
-import {Issue} from './issue';
-import {Logger} from './loggers/logger';
-import {LoggerService} from '../services/logger.service';
+import {Issue} from './issue.js';
+import {Logger} from './loggers/logger.js';
+import {LoggerService} from '../services/logger.service.js';
 
 interface IGroupValue {
   name: string;