Replace any placeholders within the rules with the values that
match the 'key' of any properties being set. For example, if
we had the following $data array:

[ 'id' => 13 ]

and the following rule:

'required|is_unique[users,email,id,{id}]'

The value of {id} would be replaced with the actual id in the form data:

'required|is_unique[users,email,id,13]'

@param array $rules
@param array $data

@return array