[PLAY-1402] hide beta versions of kits within Kit Categories (with menu.yml)

[ElisaShapiro]

What does this PR do? A clear and concise description with your runway ticket url.
PLAY-1402 ensures that beta kits are not visible on the kit_category pages of the Playbook website. This includes both PB/kit_category/category_title and PB/beta/kit_category/category_title endpoints. This PR also continues some work started in PLAY-1391 runway/PR to fully update name -> category for beta website pages based on the change to menu.yml.

The stretch goal 🌟 in the runway ticket was also achieved: menu_yml_spec.rb contains some basic tests to confirm the YAML file loads without errors, that categories and components are properly defined, and that each component has a name and a platform. Runs with rspec playbook-website/test/menu_yml_spec.rb from playbook folder.

Screenshots: Screenshots to visualize your addition/change:
Note - for these screenshots I temporarily made several kits beta on my local for the sake of a clear visual demonstration. Dialog, Button Toolbar, and Circle Icon Button are beta in the examples below.
Kits are beta - Dialog and Button Toolbar kit pages have beta kit card, not listed on sidebar:


All Kits pages - beta kits do not appear:


Kit Category pages - beta kits do not appear:


Beta All Kits page - beta kits do not appear, even when searched for in the filter input:


Beta Kit Category pages - beta kits do not appear:

How to test? Steps to confirm the desired behavior:
Note: in the milano review environment, Draggable is the only beta kit and should be used as the test kit.

1. Go to beta kit page in review env.
2. See that Draggable has the beta kit card and is not listed on sidebar under the "Layout & Structure" category.
3. Click on the "Layout & Structure" sidebar or go to kit category page in review env
4. Scroll down the page and see that Draggable is not present on the kit_category page.
5. Go to the beta kits website page and scroll down to the "Layout & Structure" category section.
6. Click on the "Layout & Structure" category title (URL will display https://pr3513.playbook.beta.gm.powerapp.cloud/beta/kit_category/layout_and_structure), see that Draggable is not present on the beta/kit_category page.

Checklist:

• LABELS Add a label: enhancement, bug, improvement, new kit, deprecated, or breaking. See Changelog & Labels for details.
• DEPLOY I have added the milano label to show I'm ready for a review.
• TESTS I have added test coverage to my code.