[frontend][landing] Create a dashboard share wrapper page

[Pedro Fortuna]

This creates a page that wraps the dashboard image to share:

The URL structure of the page is:
https://covidografia.pt/o-meu-codigo-postal/**{CODIGO_POSTAL}**/**{IMAGE_ID_WITHOUT_PNGEXTENSION}**

Only the ID of the image is needed.
The frontend code must check if the image exists.
If it does, render the normal layout (it will be added to this issue).
If it doesn't exist, then redirect to the homepage (landing page).

"Este é o estado da minha zona, como está a tua? Vê o estado da tua zona em covidografia.pt https://covidografia.pt/o-meu-codigo-postal/**{CODIGO_POSTAL}**/**{IMAGE_ID_WITHOUT_PNGEXTENSION}** #covidografia"

[Pedro Fortuna]

design:
https://www.figma.com/file/BfK7HtPsvxZAwZLg1ebz2u/Covidografia?node-id=4299%3A0

Copy is being finished directly in figma but will maintain the layout.