[ticket/11533] Columns counter for notification settings

Add columns counter template variable. It counts number of
notification types + column for name + column for checkbox

PHPBB3-11533
[ticket/11533] Change list to table for notification settings

PHPBB3-11533
[ticket/11533] Fix colspan and unnecessary tables

Fix colspan and remove unnecessary tables in notification
settings page in subsilver2.

PHPBB3-11533
[ticket/11533] Update unit tests

Update notification settings functional unit test for new layout

PHPBB3-11533
Merge remote-tracking branch 'remotes/cyberalien/ticket/11533' into develop

# By Vjacheslav Trushkin
# Via Vjacheslav Trushkin
* remotes/cyberalien/ticket/11533:
  [ticket/11533] Update unit tests
  [ticket/11533] Fix colspan and unnecessary tables
  [ticket/11533] Change list to table for notification settings
  [ticket/11533] Columns counter for notification settings