chore: move mat re-exports to package where their metadata lives (#7193)

This also required creating a module file for every component because
the max re-export can't be in the same file as the module definition or
else ngc will *only* export the alias.

src/lib/menu/menu-module.ts

@@ -0,0 +1,40 @@
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+import {NgModule} from '@angular/core';
+import {CommonModule} from '@angular/common';
+import {MdCommonModule} from '@angular/material/core';
+import {OverlayModule} from '@angular/cdk/overlay';
+import {MdMenu, MD_MENU_DEFAULT_OPTIONS} from './menu-directive';
+import {MdMenuItem} from './menu-item';
+import {MdMenuTrigger, MD_MENU_SCROLL_STRATEGY_PROVIDER} from './menu-trigger';
+import {MdRippleModule} from '@angular/material/core';
+
+
+@NgModule({
+  imports: [
+    OverlayModule,
+    CommonModule,
+    MdRippleModule,
+    MdCommonModule,
+  ],
+  exports: [MdMenu, MdMenuItem, MdMenuTrigger, MdCommonModule],
+  declarations: [MdMenu, MdMenuItem, MdMenuTrigger],
+  providers: [
+    MD_MENU_SCROLL_STRATEGY_PROVIDER,
+    {
+      provide: MD_MENU_DEFAULT_OPTIONS,
+      useValue: {
+        overlapTrigger: true,
+        xPosition: 'after',
+        yPosition: 'below',
+      },
+    }
+  ],
+})
+export class MdMenuModule {}