Summary panel a11y

[SteveJonesDev]

This PR updates the summary tiles to an unordered list with aria labels for improved a11y.

• Added helper class to output summary items as list items with aria labels.
• Update summary labels to be translatable.
• Update CSS logic
• Linked asterisk to description and added screen reader text

Fixes #359 Fixes #358

[pattonwebz]

EDIT: I seen this due to cached CSS file. Clearing the cache Isee the correct panel colors.

I tested this, and the summary works with it. There are no errors after checkout, as far as I can tell.

@SteveJonesDev I'm unsure if this is intentional, but the panels' background colour has changed with this PR.

Without PR:

After checkout and build this PR: