add toggle password-visibility feature for signup/login forms

[promaroy]

Is your feature request related to a problem? Please Describe.

Toggle password-visibility feature in forms provides a better user experience.

Additional context

As a GSSOC '21 participant, I would like to add this feature.

[promaroy]

Kindly assign me this issue

[shashankmotruri]

@promaroy make sure you read contributing guidelines.