Issue #SB-0000 fix: Added testcases for cs-lib-initializer service

src/app/client/src/app/service/CsLibInitializer/cs-lib-initializer.service.spec.ts

+import { CsLibInitializerService } from './cs-lib-initializer.service';
+import { UserService } from '@sunbird/core';
+import { CsModule } from '@project-sunbird/client-services';
+import { of } from 'rxjs';
+
+describe('CsLibInitializerService', () => {
+    let csLibInitializerService: CsLibInitializerService;
+    const mockUserService: Partial<UserService> = {
+        userData$: of({
+            userProfile: {} as any
+        }) as any,
+        appId: '123',
+    };
+    beforeEach(() => {
+        csLibInitializerService = new CsLibInitializerService(
+            mockUserService as UserService)
+    });
+
+    it('should create CsLibInitializerService', () => {
+        expect(csLibInitializerService).toBeTruthy();
+    });
+
+    it('should initialize CsModule', () => {
+        jest.spyOn(document, 'getElementById').mockReturnValue(<HTMLElement><unknown>123)
+        CsModule.instance['_isInitialised'] = false;
+        jest.spyOn(CsModule.instance, 'init');
+        csLibInitializerService.initializeCs();
+        expect(CsModule.instance.init).toHaveBeenCalled();
+        expect(CsModule.instance.isInitialised).toBeTruthy();
+
+    });
+});
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