DEV: Refactor and test plugin addKeyboardShortcut (#9381)

Refactor plugin-api `addKeyboardShortcut` to point to `KeyboardShortcuts`.
* Do not add shortcuts to the default object directly.
* Create an addShortcut function in keyboard-shortcuts to add shortcuts safely and call to bindKey to be able to use opts.
* Refactor controllers/bookmark.js to use new addShortcut func and emove unnecessary addBindings.
* No longer export keyboard shortcut bindings, rename to DEFAULT_BINDINGS and remove export, these do not need to be accessed by anything else.

test/javascripts/acceptance/plugin-keyboard-shortcut-test.js

@@ -0,0 +1,54 @@
+import { acceptance } from "helpers/qunit-helpers";
+import { withPluginApi } from "discourse/lib/plugin-api";
+import KeyboardShortcuts from "discourse/lib/keyboard-shortcuts";
+import KeyboardShortcutInitializer from "discourse/initializers/keyboard-shortcuts";
+
+function initKeyboardShortcuts() {
+  // this is here because initializers/keyboard-shortcuts is not
+  // firing for this acceptance test, and it needs to be fired before
+  // more keyboard shortcuts can be added
+  KeyboardShortcutInitializer.initialize(Discourse.__container__);
+}
+
+acceptance("Plugin Keyboard Shortcuts - Logged In", {
+  loggedIn: true
+});
+
+test("a plugin can add a keyboard shortcut", async assert => {
+  initKeyboardShortcuts();
+  withPluginApi("0.8.38", api => {
+    api.addKeyboardShortcut("]", () => {
+      $("#qunit-fixture").html(
+        "<div id='added-element'>Test adding plugin shortcut</div>"
+      );
+    });
+  });
+
+  await visit("/t/this-is-a-test-topic/9");
+  await keyEvent(document, "keypress", "]".charCodeAt(0));
+  assert.equal(
+    $("#added-element").length,
+    1,
+    "the keyboard shortcut callback fires successfully"
+  );
+});
+
+acceptance("Plugin Keyboard Shortcuts - Anonymous", {
+  loggedIn: false
+});
+
+test("a plugin can add a keyboard shortcut with an option", async assert => {
+  var spy = sandbox.spy(KeyboardShortcuts, "_bindToPath");
+  initKeyboardShortcuts();
+  withPluginApi("0.8.38", api => {
+    api.addKeyboardShortcut("]", () => {}, {
+      anonymous: true,
+      path: "test-path"
+    });
+  });
+
+  assert.ok(
+    spy.calledWith("test-path", "]"),
+    "bindToPath is called due to options provided"
+  );
+});