fix(menu): prevents defaultFocusedValue on trigger click

[geotrev]

Description

Currently, setting a defaultFocusedValue causes unexpected focus into the menu when the trigger is clicked with a mouse.

Detail

The way defaultFocusedValue should operate today is to only focus an item when the menu opens with keyboard interaction (from the trigger).

Instead, because useReducer initializes with defaultFocusedValue, a menu first opens with that value selected, including mouse interaction.

This behavior is intended to match APG examples which prefer moving focus into menus only when an item is hovered.

Note the below demonstration that showcases Hydrangea as the default focused value before and after the fix.

Before:

Screen.Recording.2024-09-12.at.12.28.50.PM.mov

After:

Screen.Recording.2024-09-12.at.12.34.38.PM.mov

Checklist

• 🌐 demo is up-to-date (npm start)
• 💂‍♂️ includes new unit tests
• ♿ tested for WCAG 2.1 AA compliance
• 📝 tested in Chrome, Firefox, Safari, and Edge

[coveralls]

coverage: 95.716% (-0.003%) from 95.719%
when pulling cd668dd on george/menu-default-value-fix
into 482fbf0 on main.