Extract methods in votes components

This way we can make the view code a bit easier to read.

We're also changing the order of the conditions a little bit so we only
check for the presence of a current user once.

To make sure we aren't breaking anything with these changes, we're
adding some tests. We're also replacing one system test checking content
with a component test, since component tests are much faster.

app/components/proposals/votes_component.rb

@@ -10,4 +10,18 @@ class Proposals::VotesComponent < ApplicationComponent
   def vote_url
     @vote_url || vote_proposal_path(proposal, value: "yes")
   end
+
+  private
+
+    def voted?
+      current_user&.voted_for?(proposal)
+    end
+
+    def can_vote?
+      proposal.votable_by?(current_user)
+    end
+
+    def organization?
+      current_user&.organization?
+    end
 end