Make it possible to disable tenants

Note we could use `acts_as_paranoid` with the `without_default_scope`
option, but we aren't doing so because it isn't possible to consider
deleted records in uniqueness validations with the paranoia gem [1].
I've added tests for these cases so we don't accidentally add
`acts_as_paranoid` in the future.

Also note we're extracting a `RowComponent` because, when
enabling/disabling a tenant, we're also enabling/disabling the link
pointing to its URL, and so we need to update the URL column after the
AJAX call.

[1] See issues 285 and 319 in https://github.com/rubysherpas/paranoia/

app/controllers/admin/tenants_controller.rb

@@ -27,6 +27,24 @@ class Admin::TenantsController < Admin::BaseController
     end
   end
 
+  def hide
+    @tenant.hide
+
+    respond_to do |format|
+      format.html { redirect_to admin_tenants_path, notice: t("admin.tenants.hide.notice") }
+      format.js { render template: "admin/tenants/toggle_enabled" }
+    end
+  end
+
+  def restore
+    @tenant.restore
+
+    respond_to do |format|
+      format.html { redirect_to admin_tenants_path, notice: t("admin.tenants.restore.notice") }
+      format.js { render template: "admin/tenants/toggle_enabled" }
+    end
+  end
+
   private
 
     def tenant_params