feat(performance): Major performance improvements using async v2 from @oberblastmeister (#987)

* start: Working w/ async jobs

* short circuit to using bad finder if you pass writer.

lua/telescope/entry_manager.lua

@@ -155,7 +155,10 @@ function EntryManager:add_entry(picker, score, entry)
     info.looped = info.looped + 1
 
     if container[2] > score then
-      -- print("Inserting: ", picker, index, node, new_container)
+      return self:_insert_container_before(picker, index, node, new_container)
+    end
+
+    if score < 1 and container[2] == score and #entry.ordinal < #container[1].ordinal then
       return self:_insert_container_before(picker, index, node, new_container)
     end
 
@@ -174,11 +177,13 @@ function EntryManager:add_entry(picker, score, entry)
 end
 
 function EntryManager:iter()
-  return coroutine.wrap(function()
-    for val in self.linked_states:iter() do
-      coroutine.yield(val[1])
+  local iterator = self.linked_states:iter()
+  return function()
+    local val = iterator()
+    if val then
+      return val[1]
     end
-  end)
+  end
 end
 
 return EntryManager