Use render_map to render the admin settings map

This way we remove duplication.

Note that to check whether to render the button to remove a marker,
we're checking whether the map location belongs to a mappable. This
means we're changing the code that renders the map in the "new proposal"
and "new investment" forms so the map location belongs to a proposal or
investment. We're association the map location to a new record because
writing something like:

```
def map_location
  proposal.map_location || MapLocation.new(proposal: proposal)
end
```

Would change the `proposal` object because of the way Rails treats
non-persisted `has_one` associations. Although probably safe in this
case, changing an object when rendering a view could have side effects.

Also note that we're changing the HTML ID of the map element from
`admin-map` to `new_map_location` (the latter is returned by the
`dom_id` method).  We were only using this ID in tests since commit
289426c1c, so changing it doesn't really affect us.

spec/components/admin/settings/map_form_component_spec.rb

@@ -0,0 +1,10 @@
+require "rails_helper"
+
+describe Admin::Settings::MapFormComponent do
+  it "does not render a button to remove the marker" do
+    render_inline Admin::Settings::MapFormComponent.new
+
+    expect(page).to have_css ".map-location"
+    expect(page).not_to have_button "Remove map marker"
+  end
+end

spec/components/budgets/investments/form_component_spec.rb

@@ -33,4 +33,17 @@ describe Budgets::Investments::FormComponent do
       expect(page).not_to have_field "I agree to the Privacy Policy and the Terms and conditions of use"
     end
   end
+
+  describe "map" do
+    it "renders a button to remove the map marker" do
+      Setting["feature.map"] = true
+
+      render_inline Budgets::Investments::FormComponent.new(
+        budget.investments.new,
+        url: budget_investments_path(budget)
+      )
+
+      expect(page).to have_button "Remove map marker"
+    end
+  end
 end

spec/components/proposals/form_component_spec.rb

@@ -0,0 +1,17 @@
+require "rails_helper"
+
+describe Proposals::FormComponent do
+  include Rails.application.routes.url_helpers
+
+  before { sign_in(create(:user)) }
+
+  describe "map" do
+    it "renders a button to remove the map marker" do
+      Setting["feature.map"] = true
+
+      render_inline Proposals::FormComponent.new(Proposal.new, url: proposals_path)
+
+      expect(page).to have_button "Remove map marker"
+    end
+  end
+end

spec/components/shared/map_location_component_spec.rb

@@ -0,0 +1,31 @@
+require "rails_helper"
+
+describe Shared::MapLocationComponent do
+  describe "remove marker button" do
+    it "is not rendered when there's no form" do
+      map_location = build(:map_location, proposal: Proposal.new)
+
+      render_inline Shared::MapLocationComponent.new(map_location)
+
+      expect(page).not_to have_button "Remove map marker"
+    end
+
+    it "is not rendered when there's no mappable" do
+      map_location = build(:map_location)
+      form = ConsulFormBuilder.new(:map_location, map_location, ApplicationController.new.view_context, {})
+
+      render_inline Shared::MapLocationComponent.new(map_location, form: form)
+
+      expect(page).not_to have_button "Remove map marker"
+    end
+
+    it "is rendered when there's a form and a mappable" do
+      map_location = build(:map_location, proposal: Proposal.new)
+      form = ConsulFormBuilder.new(:map_location, map_location, ApplicationController.new.view_context, {})
+
+      render_inline Shared::MapLocationComponent.new(map_location, form: form)
+
+      expect(page).to have_button "Remove map marker"
+    end
+  end
+end

spec/system/admin/settings_spec.rb

@@ -26,11 +26,11 @@ describe "Admin settings", :admin do
 
       visit admin_settings_path
 
-      expect(page).not_to have_css "#admin-map.leaflet-container", visible: :all
+      expect(page).not_to have_css ".map-location.leaflet-container", visible: :all
 
       click_link "Map configuration"
 
-      expect(page).to have_css "#admin-map.leaflet-container"
+      expect(page).to have_css ".map-location.leaflet-container"
     end
   end
 
@@ -44,7 +44,7 @@ describe "Admin settings", :admin do
       expect(page).to have_content "To show the map to users you must enable " \
                                    '"Proposals and budget investments geolocation" ' \
                                    'on "Features" tab.'
-      expect(page).not_to have_css("#admin-map")
+      expect(page).not_to have_css ".map-location"
     end
 
     scenario "Should update marker" do
@@ -53,7 +53,7 @@ describe "Admin settings", :admin do
       visit admin_settings_path
       click_link "Map configuration"
 
-      expect(page).to have_css("#admin-map")
+      expect(page).to have_css ".map-location"
       expect(page).not_to have_content "To show the map to users you must enable " \
                                        '"Proposals and budget investments geolocation" ' \
                                        'on "Features" tab.'
@@ -62,7 +62,7 @@ describe "Admin settings", :admin do
       expect(page).to have_field "Longitude", with: "0.0"
 
       within "#map-form" do
-        find("#admin-map").click
+        find(".map-location").click
         click_button "Update"
       end