[UX] Move new password show/hide toggle to inside the password fields.

Describe your issue or idea

I was on the internet filling out a account sign up form and they had there password view/hide toggle in the password field and I liked it.

Steps to reproduce (if reporting a bug)

Either install a Backdrop site or visit /user/%/edit page.

Actual behavior (if reporting a bug)

Password toggle is a link above the password field.

Expected behavior (if reporting a bug)

Move the button inside the password field.

Relevant version/system information (if applicable)

1.x