Remove votes query optimizations

Just like we did in commit 0214184b2d for investments, we're removing
some possible optimizations (we don't have any benchmarks proving they
affect performance at all) in order to simplify the code.

The investement votes component `delegate` code was accidentally left
but isn't used since commit 0214184b2, so we're removing it now that
we're removing the `voted_for?` helper method.

app/controllers/application_controller.rb

@@ -68,14 +68,6 @@ class ApplicationController < ActionController::Base
       end
     end
 
-    def set_debate_votes(debates)
-      @debate_votes = current_user ? current_user.debate_votes(debates) : {}
-    end
-
-    def set_proposal_votes(proposals)
-      @proposal_votes = current_user ? current_user.proposal_votes(proposals) : {}
-    end
-
     def set_comment_flags(comments)
       @comment_flags = current_user ? current_user.comment_flags(comments) : {}
     end