Cleanup typography + Remove maintenance page

[davinotdavid]

Description of the Change

• Removes old typography (Open Sans, Raleway and Roboto) leaving only Inter and Metropolis.
• Uses "Inter" as the standard sans serif in the Tailwind config (while we don't fully remove Tailwind).
• Removes the unused / unreachable maintenance page. To add one again, we need to update CloudFront configurations in order to actually serve it so it wouldn't be a simple style change).

How to test

• Clean & build all containers locally and navigate through the pages.
• Inspect various text on screen and check the CSS for font-family. It should always be either Inter or metropolis.

Benefits

• Less unused imports and better cohesion in the UI regarding typography.

Applicable Issues

Fixes #1435

[MelissaAutumn]

lgtm, we use to have a font selector in settings so that's why we had so many fonts available.

[davinotdavid]

@MelissaAutumn oooh interesting! I didn't know that, thanks for the background info!