feat(PPDSC-2609): submenu overrides and href

[mutebg]

PPDSC-2609

What

1. Background - why this is needed
2. What did you do -
   2.1. Added new defaults to SubMenu and SubMenu items.
   2.2. Changed types so href can be passed as prop to SubMenu
   2.3. Updated Menu Context so that we know when a menu-item is in sub-menu or main menu and apply different style-preset
   2.4. Updated docs
3. What does the reviewers should expect

I have done:

• Written unit tests against changes
• Written functional tests against the component and/or NewsKit site
• Updated relevant documentation

I have tested manually:

• The feature's functionality is working as expected on Chrome, Firefox, Safari and Edge
• The screen reader reads and flows through the elements as expected.
• There are no new errors in the browser console coming from this PR.
• When visual test is not added, it renders correctly on different browsers and mobile viewports (Safari, Firefox, small mobile viewport, tablet)
• The Playground feature is working as expected

Before:

After:

Who should review this PR:

How to test:

[newskit-engineering]

You can preview these changes on:
Documentation Site: http://ncu-newskit-docs.s3-website-eu-west-1.amazonaws.com/ppdsc-2609-submenu-overrides
Storybook: http://ncu-newskit-docs.s3-website-eu-west-1.amazonaws.com/ppdsc-2609-submenu-overrides/storybook

[baburay23]

looks good to me my only question is..now that you added href prop to submenu is the below still needed? i noticed as well that prop href has not been added to the prop API table. Is there a reason for that? sorry maybe i am missing something!

[mutebg]

looks good to me my only question is..now that you added href prop to submenu is the below still needed? i noticed as well that prop href has not been added to the prop API table. Is there a reason for that? sorry maybe i am missing something!

thanks for finding these, removed the message and added href prop