feat(ui): Update buttons to v3

Related to issue #424 (closed), as part of #427 (closed)

What does this MR do and why?

Replaced the buttons with the v3 versions, except:

• the ones aiming to become tags
• the one (only one?) aiming to become a toggle (signup to the newsletter)

Some of them are too narrow to fit their text in one line, they all have been reported within Figma.