Add new settings tab for participation processes

- Rename setting keys
- New tab por participation processes
- Hide these settings from features tab

spec/features/valuation/budget_investments_spec.rb

@@ -12,7 +12,7 @@ feature "Valuation budget investments" do
   end
 
   scenario "Disabled with a feature flag" do
-    Setting["feature.budgets"] = nil
+    Setting["process.budgets"] = nil
     expect{
       visit valuation_budget_budget_investments_path(create(:budget))
     }.to raise_exception(FeatureFlags::FeatureDisabled)