Add show password option on sign in, sign up and forgot password forms

Is your feature request related to a problem? Please describe.
Problem

We’ve had a lot of support tickets from users who had a really hard time typing a 10 character long password twice without making any error.

As there isn’t instant input validation on the password field many ran into the error “passwords do not match” several times when sending the form.

For existing users who tried to sign in, not being able to see what they were typing leads to think they forgot their password.

During user testing we’ve seen users type their password in the email field first (sometimes on an external text editor) and then copy paste it in the password field to make sure they weren’t making any mistakes. On mobile this can be particularly painful for the user.

Describe the solution you'd like
As a user who needs to type a password on a Decidim form I should have a show password option so I can proofread what I’m typing.

On most website this option is offered directly on the field using an eye icon. For accessibility reasons we think it might be better to add a checkbox bellow the password fields (like twitter is doing).

Describe alternatives you've considered
Get rid of password using magic links (External link)

Additional context
This proposal is part of a larger scope to improve authentication flow in Decidim. Working document here (External link).

Does this issue could impact on users private data?
No

Funded by
Angers and OSP