Add the ability for a customizer control to render its controls via a JavaScript template. Switches the default color picker control to a JavaScript template. See #29572. Props celloexpressions

git-svn-id: https://develop.svn.wordpress.org/trunk@30014 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-admin/customize.php

@@ -180,6 +180,9 @@ do_action( 'customize_controls_print_scripts' );
 	<div id="customize-preview" class="wp-full-overlay-main"></div>
 	<?php
 
+	// Render control templates.
+	$wp_customize->render_control_templates();
+
 	/**
 	 * Print Customizer control scripts in the footer.
 	 *