[ticket/11717] Use topic_posts_approved instead of topic_replies

Due to the move to soft-delete, the topic_replies column no longer exists
in the topics table. Instead, the column topic_posts_approved should be used.

PHPBB3-11717
[ticket/11717] Add 'has' to boolean variable and reduce line length

PHPBB3-11717
Merge pull request #1589 from marc1706/ticket/11717

[ticket/11717] Use topic_posts_approved instead of topic_replies
[ticket/11728] Replace topic_approved with topic_visibility

PHPBB3-11728
Merge remote-tracking branch 'nickvergessen/ticket/11728' into develop

* nickvergessen/ticket/11728:
  [ticket/11728] Replace topic_approved with topic_visibility
[ticket/11731] Remove static calls to captcha garbage collector

PHPBB3-11731
Merge remote-tracking branch 'asperous/ticket/11731' into develop

* asperous/ticket/11731:
  [ticket/11731] Remove static calls to captcha garbage collector