[feature/api] Added exception throwing to post and topic

The post and topic repository now throws a
phpbb_model_exception_no_permission_exception if not having
permission to do the action.

PHPBB3-11595
[feature/api] Added pagination to topics and post lists

Now lists current page, the last page, topics/posts per page
and how many topics/posts there are, for easier pagination.

PHPBB3-11595