[login] Improve request account email

[skarya22]

Brief summary of changes

• Update the request account email to have more useful information
  Before:
  
  After:
  

Testing instructions (if applicable)

1. Disable sandbox and set your user to receive request account emails (Change Sandbox in project/config.xml to be 0, and in modules/login/php/signup.class.inc just change line 252 to be your email)
2. Request an account and check your email

[driusan]

I approve Persephone Arya's account but have no particular feelings about this pull request.

[skarya22]

@driusan Main goal was to add the URL at the bottom + the site as the email did not include site before

[AdamAlAttrach]

LGTM