Remove duplicate map location translations

We were using the same texts twice. For the remove marker label text,
however, we were using the text defined in proposals for both proposals
and investments.

Ideally the translation keys for these texts would go in another
namespace, since they no longer refer to just proposals. However,
renaming the translation keys would mean losing the existing
translations in every language we manage through Crowdin. So we aren't
doing so.

spec/components/map_locations/form_fields_component_spec.rb

@@ -4,11 +4,7 @@ describe MapLocations::FormFieldsComponent do
   let(:proposal) { Proposal.new }
   let(:map_location) { MapLocation.new }
   let(:form) { ConsulFormBuilder.new(:proposal, proposal, ApplicationController.new.view_context, {}) }
-  let(:label) { "Map location" }
-  let(:help) { "Add a marker" }
-  let(:component) do
-    MapLocations::FormFieldsComponent.new(form, map_location: map_location, label: label, help: help)
-  end
+  let(:component) { MapLocations::FormFieldsComponent.new(form, map_location: map_location) }
 
   it "is rendered when the map feature is enabled" do
     Setting["feature.map"] = true