Change to metafield type handling in liquid

Themes

Effectively immediately, metafields without a type value will return "string" instead of blank. For example, this check will no longer be true liquid {% if metafield.type == blank %} This will no longer render. {% endif %}

Instead, a value of string will be returned: liquid {% if metafield.type == 'string' %} This metafield is of type `string`. {% endif %}