refactor(settings): remove blocked addresses setting and block user/board feature

Obsolete with pseudonymity mode (user IDs randomized per board) and custom boards
requiring explicit search/subscribe. Unsubscribe suffices for boards.

public/translations/en/default.json

@@ -141,15 +141,6 @@
   "posts_last_synced_info": "Posts last synced {{time}}, this board might be offline and publishing might fail.",
   "newer_than": "newer than",
   "no_threads": "No threads",
-  "unblock": "Unblock",
-  "unblock_all": "Unblock all",
-  "blocked_addresses": "Blocked addresses",
-  "you_have_not_blocked": "You have not blocked any board address or user address.",
-  "block_user": "Block user",
-  "unblock_user": "Unblock user",
-  "block_board": "Block board",
-  "unblock_board": "Unblock board",
-  "unblock_all_confirm": "Are you sure you want to unblock all board addresses and user addresses?",
   "hidden": "hidden",
   "save_options": "Save Options",
   "filters": "filters",
@@ -227,7 +218,6 @@
   "field_too_long": "Field too long.",
   "unsubscribe_all": "Unsubscribe From All",
   "unsubscribe_all_confirm": "Are you sure you want to unsubscribe from all boards?",
-  "you_have_blocked_this_board": "You have blocked this board",
   "looking_for_more_posts": "Looking for more posts",
   "loading_feed": "Loading feed",
   "loading_post": "Loading post",