Login: make the "email me login link" button more visible

I really miss how hidden that "email me login link" is, especially on mobile where it's super useful. (I bet this is visible from data)

Thoughts on if it should be more visible and how?

_Originally posted by @simison in https://github.com/Automattic/wp-calypso/issues/52877#issuecomment-845736367_

Screenshot with the "email me login link" on the login screen:

Start by locating the login screen and the “email me login link” button referenced in the issue, then review the attached screenshot and mobile layout. Confirm the desired visibility treatment with maintainers before changing anything; the issue does not define acceptance criteria or what done looks like.

Written by the indexing model from the issue text.