personal_menu: Add tippy personal_menu dropdown.

Add a personal menu dropdown that opens on clicking user avatar icon
in navbar added in previous commit.

The args passed to render_personal_menu() in onShow() are returned by
get_personal_menu_content_context() in popover_menus_data.js so that
they can be unit tested.

Additionally, added CSS to get a custom arrow for dropdown menu.

Added a `?` hotkey in keyboard shortcuts option in personal_menu
dropdown in a style similar to our tooltip's hotkey by adding
? in a span with class .tooltip-hotkey-hint and adding some CSS.

Fixes part of #22802.

web/src/click_handlers.js

@@ -926,4 +926,10 @@ export function initialize() {
     $(".settings-header.mobile .fa-chevron-left").on("click", () => {
         settings_panel_menu.mobile_deactivate_section();
     });
+
+    $("body").on("click", ".trigger-natural-click", (e) => {
+        // Jquery prevents default action on anchor for `trigger("click")`
+        // so we need to use click on element to trigger the default action.
+        e.currentTarget.click();
+    });
 }