refactor(cdk-experimental/menu): rename cdk selectable output and add cdk specific output naming

src/cdk-experimental/menu/menu-group.ts

@@ -63,7 +63,7 @@ export class CdkMenuGroup implements AfterContentInit, OnDestroy {
 
   /** Register each selectable to emit on the change Emitter when clicked */
   private _registerClickListener(selectable: CdkMenuItemSelectable) {
-    selectable.clicked
+    selectable.toggled
       .pipe(takeUntil(this._selectableChanges))
       .subscribe(() => this.change.next(selectable));
   }

src/cdk-experimental/menu/menu-item-checkbox.spec.ts

@@ -78,7 +78,7 @@ describe('MenuItemCheckbox', () => {
 
   it('should emit on clicked emitter when triggered', () => {
     const spy = jasmine.createSpy('cdkMenuItemCheckbox clicked spy');
-    checkbox.clicked.subscribe(spy);
+    checkbox.toggled.subscribe(spy);
 
     checkbox.trigger();
 
@@ -87,7 +87,7 @@ describe('MenuItemCheckbox', () => {
 
   it('should not emit on clicked emitter when disabled', () => {
     const spy = jasmine.createSpy('cdkMenuItemCheckbox clicked spy');
-    checkbox.clicked.subscribe(spy);
+    checkbox.toggled.subscribe(spy);
     checkbox.disabled = true;
 
     checkbox.trigger();

src/cdk-experimental/menu/menu-item-radio.spec.ts

@@ -74,7 +74,7 @@ describe('MenuItemRadio', () => {
 
   it('should emit on clicked emitter when triggered', () => {
     const spy = jasmine.createSpy('cdkMenuItemRadio clicked spy');
-    radioButton.clicked.subscribe(spy);
+    radioButton.toggled.subscribe(spy);
 
     radioButton.trigger();
 
@@ -83,7 +83,7 @@ describe('MenuItemRadio', () => {
 
   it('should not emit on clicked emitter when disabled', () => {
     const spy = jasmine.createSpy('cdkMenuItemRadio clicked spy');
-    radioButton.clicked.subscribe(spy);
+    radioButton.toggled.subscribe(spy);
     radioButton.disabled = true;
 
     radioButton.trigger();

src/cdk-experimental/menu/menu-item-selectable.ts

@@ -20,7 +20,7 @@ let nextId = 0;
 @Directive()
 export abstract class CdkMenuItemSelectable extends CdkMenuItem {
   /** Event emitted when the selectable item is clicked */
-  @Output() clicked: EventEmitter<CdkMenuItemSelectable> = new EventEmitter();
+  @Output('cdkMenuItemToggled') toggled: EventEmitter<CdkMenuItemSelectable> = new EventEmitter();
 
   /** Whether the element is checked */
   @Input()
@@ -41,7 +41,7 @@ export abstract class CdkMenuItemSelectable extends CdkMenuItem {
   /** If the element is not disabled emit the click event */
   trigger() {
     if (!this.disabled) {
-      this.clicked.next(this);
+      this.toggled.next(this);
     }
   }