feat(cdk-experimental/menu): add functionality to navigate a Menu and MenuBar with a keyboard (#19962)

The aria spec for Menu and MenuBar describes a robust set of instructions for navigating the Menu
using a keyboard. This implements the full aria spec for vertical and horizontal Menus along with
support for left-to-right and right-to-left layouts. Some liberty is taken with handling keyboard
events with modifier keys (home/end and escape) in order to match the existing mat-menu
implementation for those keys.

Author: andy9775

src/cdk-experimental/menu/BUILD.bazel

@@ -10,9 +10,11 @@ ng_module(
     ),
     module_name = "@angular/cdk-experimental/menu",
     deps = [
+        "//src/cdk/a11y",
         "//src/cdk/bidi",
         "//src/cdk/coercion",
         "//src/cdk/collections",
+        "//src/cdk/keycodes",
         "//src/cdk/overlay",
         "@npm//@angular/core",
         "@npm//rxjs",
@@ -28,6 +30,8 @@ ng_test_library(
     deps = [
         ":menu",
         "//src/cdk/collections",
+        "//src/cdk/keycodes",
+        "//src/cdk/testing/private",
         "@npm//@angular/platform-browser",
     ],
 )