[`json_validate` function](https://wiki.php.net/rfc/json_validate)
[added in PHP 8.3](https://php.watch/versions/8.3/json_validate) validates a
given string input to contain valid JSON without decoding it in memory.
This adds a function availability check to `Rules\Json`, and uses the new
function instead of decoding the given input, followed by a last-error check.
According to the official documentation [1] the correct way of writing
the "inheritDoc" tag is with the uppercase "D".
[1]: https://docs.phpdoc.org/guides/inheritance.html
Signed-off-by: Henrique Moody <henriquemoody@gmail.com>
This commit will add a couple of rules that we already use but also
introduce new ones and make sure all the code is in accordance with the
new coding standards.
Signed-off-by: Henrique Moody <henriquemoody@gmail.com>
