add: don't allow poll creator to vote

add: unfollow user when you block them
add: force other user to unfollow you by blocking them
add: leave receiver communities when you block them

crates/core/src/database/stacks.rs

@@ -51,7 +51,7 @@ impl DataManager {
             Community,
             Option<(User, Post)>,
             Option<(Question, User)>,
-            Option<(Poll, bool)>,
+            Option<(Poll, bool, bool)>,
         )>,
     > {
         let stack = self.get_stack_by_id(id).await?;