[bd] API 1.6.3

• PHP 7.3 support
• Added GET `/users/fields`
• Added POST `/lost-password`
• Added GET `/threads/:threadId/navigation`
• Added GET `/posts/unread`
• Added POST `/notifications/custom`
• Added GET `/threads/:threadId/poll`
• Added param `fields` for POST `/users`
• Added param `before` and `after` for GET `/conversation-messages`
• Added param `thread_create_date` and `thread_update_date` for GET `/threads`
• Added `ids` into response of GET `/tags/find`
• Added `last_message` into conversation data
• Added avatar links into recipient data
• Added `thread_is_new` and `links.posts_unread` into thread data
• Added `user_is_admin`, `user_is_moderator` and `user_is_staff` into user data
• Added `like_users` into post data
• Added `follow_date` and user data into response of GET `/users/:userId/followers` and GET `/users/:userId/followings`
• Added support for `Api-Username-Inline-Style` header
• Other performance improvements and bug fixes