Allow autocompletion for email and password inputs

[alajusticia]

This pull request allows web browsers and password managers to autocomplete the email and password inputs:

• adding the autocomplete on email and password inputs
• adding the name property where missing (in order to provide autocompletion, user-agents might require inputs to have a name and/or id attribute)

In the login page, I've made sure that the password input is present in the DOM right from the start, because otherwise in some cases the credentials autocompletion doesn't work (for example with the Google Password Manager in Chrome).
The password input is hidden by default and I change its CSS classes to show it when required.

[tnylea]

Thanks @alajusticia!

It looks good. I'll get this merged in tomorrow 👏

[tnylea]

I'm going to merge this into the allow-autocomplete branch and then I'll merge that into main to make sure all the tests pass.

Here is the PR that will be merged into main ;) #144