Allow invite group modal to render when membership is locked

- should be allowed to invite a group to a project, even
  when group membership is locked.

Changelog: fixed
EE: true

app/views/projects/_invite_groups_modal.html.haml

-- return unless can_admin_project_member?(project)
+- return unless can_invite_members_for_project?(project)
 
 .js-invite-groups-modal{ data: common_invite_group_modal_data(project, ProjectMember, 'true') }

ee/spec/views/projects/project_members/index.html.haml_spec.rb

@@ -29,9 +29,11 @@ RSpec.describe 'projects/project_members/index', :aggregate_failures do
         expect(rendered).to have_content('You can invite another group to')
         expect(rendered).not_to have_link('Import from a project')
         expect(rendered).to have_selector('.js-invite-group-trigger')
+        expect(rendered).to have_selector('.js-invite-groups-modal')
         expect(rendered).not_to have_selector('.js-invite-members-trigger')
         expect(rendered).not_to have_content('Members can be added by project')
         expect(response).to render_template(partial: 'projects/_invite_members_modal')
+        expect(response).to render_template(partial: 'projects/_invite_groups_modal')
       end
 
       context 'when project can not be shared' do
@@ -44,6 +46,8 @@ RSpec.describe 'projects/project_members/index', :aggregate_failures do
 
           expect(rendered).to have_content('Project members')
           expect(rendered).not_to have_content('You can invite')
+          expect(rendered).not_to have_selector('.js-invite-group-trigger')
+          expect(response).not_to render_template(partial: 'projects/_invite_groups_modal')
           expect(response).to render_template(partial: 'projects/_invite_members_modal')
         end
       end