New ADMIRALTY Card component theme

[UXdave-alexander]

Is your feature request related to a problem? Please describe.
Existing ADMIRALTY card is limited in design / functionality.

Describe the solution you'd like
A new CSS variable theme to enable customisaiotn of the card header colour, additional drop shadow on card and ability to pass custom HTML into card header
(https://www.figma.com/file/LlGaslsnzKuEl0HuACXk5c/UKHO-Figma-Design-System?type=design&node-id=3865%3A5788&mode=design&t=2CTd4zbnNPVDigId-1)

Describe alternatives you've considered
N / A - usage already functioning in Sailing Directions.

Additional context

[KatiePUX]

Conversation with Dave Alexander re: need for this ticket now we have CSS variables and the new pill component is in progress, as users will be able to create this by enhancing the current card themselves using. Dave explained that user can now adjust the existing card it should not be a need anymore.

Could we create a story on the component page about enhancing the card and how this has been done in another application,,,?

[KatiePUX]

As in refinement all we need to do at this stage is add a story to the card component page that shows a more comprehensive/ complex example of adding HTML to card content and changing header colour.

[github-actions]

🚀 Issue was released in v4.0.0 🚀