Add additional token for URL encoded email address

Problem/Motivation

This module is awesome! For our use case we want to build a clickable link that can be emailed on POST to /user/lost-password request that contains all the information needed to construct the body of the post to /user/lost-password-reset.

In order to add the email address to the URL, we need to url encode the email and make that available in a token.

Proposed resolution

Make a new token, user:mail-url-encode, to be made available in rest_password_mail_tokens().

Remaining tasks

None.

User interface changes

None.

API changes

None.

Data model changes

None.