Modlog API subject

[olorin99]

The subject field for the MagazineLogResponseDto isn't documented.
From testing it looks like it is
EntryResponseDto when type is log_entry_deleted, log_entry_restored
PostResponseDto when type is log_post_deleted, log_post_restored
EntryCommentResponseDto when type is log_entry_comment_deleted, log_entry_comment_restored
PostCommentResponseDto when type is log_post_comment_deleted, log_post_comment_restored
MagazineBanDto when type is log_ban, log_unban
null when type is log_moderator_add, log_moderator_remove
{visibillity: $visible} when type is log_entry_pinned, log_entry_unpinned.

I think it would be good if subject for log_entry_pinned and log_entry_unpinned types was changed to EntryResponseDto in order to know which entry was pinned/unpinned.
Also as mentioned in #1923 to set the modded/unmodded user as subject for log_moderator_add and log_moderator_remove.