Catching when wp_json_encode() would be more applicable

[gudmdharalds]

In some instances using wp_json_encode() is more applicable than esc_attr() and esc_url(), for instance here:

<script type='text/javascript'>

somefunction('somefuncprefix_<?php echo esc_attr( $myid ); ?>_div').setup({
   file: '<?php echo esc_url( $myurl ); ?>',
})

</script>

The ruleset should catch these.

[rebeccahum]

Related: #113 -- Closing in favour of it.