Extract method to render an admin table action

This way it will be easier to change the behavior of all table actions,
like adding ARIA attributes. In the past, when we changed the behavior
of the `link_to` method, we had to change all table action classes.

spec/components/admin/action_component_spec.rb

@@ -0,0 +1,9 @@
+require "rails_helper"
+
+describe Admin::ActionComponent do
+  it "includes an HTML class for the action" do
+    render_inline Admin::ActionComponent.new(:edit, double, path: "/")
+
+    expect(page).to have_css "a.edit-link"
+  end
+end