[ticket/12533] Make <a> use all the notification item size

Changed padding CSS to the notifications' `<li>` and it's
`<a>` (immediate child) so that the `<a>` block uses all
 it's container width and height.

To compensate that, I added the padding that was in the
`<li>` to the `<a>`

PHPBB3-12533
[ticket/12533] Make <a> use all the "see all" "button"

Changed the CSS so that the `<a>` of the notifications
list for the "see all" uses all the container.

PHPBB3-12533
[ticket/12547] Rename jquery.js to jquery.min.js in assets directory

phpBB uses the minified version of jQuery hence the rename.

PHPBB3-12547
Merge remote-tracking branch 'brunoais/ticket/PHPBB3-12533' into develop-ascraeus

* brunoais/ticket/PHPBB3-12533:
  [ticket/12533] Make <a> use all the "see all" "button"
  [ticket/12533] Make <a> use all the notification item size
[ticket/12525] Add string argument to contact and email user language variables

In language/en/common.php:
* Introduce a new language variable 'CONTACT' => 'Contact'
* Add a string argument to lang var 'CONTACT_USER' to avoid an appended
 '{USERNAME}' in template.
* Add a string argument to lang var 'SEND_EMAIL_USER' to avoid an appended
 '{USERNAME}' in template.

Also fix typos.

PHPBB3-12525
Merge remote-tracking branch 'n-aleha/ticket/12525' into develop-ascraeus

* n-aleha/ticket/12525:
  [ticket/12525] Add string argument to contact and email user language variables
Merge remote-tracking branch 'n-aleha/ticket/12547' into develop-ascraeus

* n-aleha/ticket/12547:
  [ticket/12547] Rename jquery.js to jquery.min.js in assets directory