Automated native_function_invocation fixes

[draco2003]

Reproduce with:
php php-cs-fixer --rules=native_function_invocation fix ./ --allow-risky=yes
(php-cs-fixer from : https://cs.symfony.com/)

Details:
https://veewee.github.io/blog/optimizing-php-performance-by-fq-function-calls/

[ob-stripe]

Hi @draco2003, thanks for the contribution! We're actually already using PHP CS Fixer to format the library's code, but I didn't know about this rule.

I'm generally in favor of this change, but it looks like one of the tests is no longer passing. Mind taking a closer look? Otherwise I'm happy to do so myself when I have a chance.

[draco2003]

Thanks for the quick response.
Let me take a look and see If i can fix the test failure issue.
Other Repos with this similar PR failed due to particular mocking of builtin functions.

[draco2003]

Quick question based on other libraries feedback.
Would you perfer the \is_array syntax or the:
use function is_array;

?

[ob-stripe]

Quick question based on other libraries feedback.
Would you perfer the \is_array syntax or the:
use function is_array;

?

I'd prefer \is_array.

[ob-stripe]

Closed in favor of #858.