fix(@angular-devkit/core): classify string util should concat string without using a .

`.` is not a valid character in ES6 class names.

Prior to this change `foo.module` before used to be incorrectly classified to `Foo.Module` instead of `FooModule`.

Closes #13824

Author: alan-agius4

packages/angular_devkit/core/src/utils/strings.ts

@@ -74,13 +74,14 @@ export function camelize(str: string): string {
 /**
  Returns the UpperCamelCase form of a string.
 
+ @example
  ```javascript
  'innerHTML'.classify();          // 'InnerHTML'
  'action_name'.classify();        // 'ActionName'
  'css-class-name'.classify();     // 'CssClassName'
  'my favorite items'.classify();  // 'MyFavoriteItems'
+ 'app.component'.classify();      // 'AppComponent'
  ```
-
  @method classify
  @param {String} str the string to classify
  @return {String} the classified string
@@ -89,7 +90,7 @@ export function classify(str: string): string {
   return str
     .split('.')
     .map((part) => capitalize(camelize(part)))
-    .join('.');
+    .join('');
 }
 
 /**

packages/schematics/angular/class/index_spec.ts

@@ -83,7 +83,7 @@ describe('Class Schematic', () => {
     const tree = await schematicRunner.runSchematicAsync('class', options, appTree).toPromise();
     const classPath = '/projects/bar/src/app/foo.model.ts';
     const content = tree.readContent(classPath);
-    expect(content).toMatch(/export class Foo/);
+    expect(content).toMatch(/export class FooModel/);
   });
 
   it('should respect the path option', async () => {