Fix duplicate support_title I18n key

The key was declared twice and so the first one ("Support this project")
was overwritten.

We're grouping all keys related to the investment list together in order
to reduce the chances of this issue happening again (or, at least, in
this part of the code).

spec/system/budgets/votes_spec.rb

@@ -42,7 +42,7 @@ describe "Votes" do
         visit budget_investments_path(budget, heading_id: heading.id)
 
         within(".supports") do
-          find(".in-favor a").click
+          click_link "Support this project"
 
           expect(page).to have_content "1 support"
           expect(page).to have_content "You have already supported this investment project. "\