Maintenance Work

[razvanphp]

• Add github actions, fix phpunit tests
• Repacked the test p12 cert so it works with openssl3 in PHP 8.2, see https://www.php.net/manual/en/function.openssl-pkcs12-read.php#128992
• Remove unused circleci, scrutinizer and travis configs
• Add PHP_CodeSniffer (phpcs) config for PSR12 standard, fix all errors and add it as github actions step
• Add test coverage badge somewhere from scrutinizer
• Add PHPStan analyse

[eymengunay]

Hey @razvanphp,

Thank you so much for your valuable contribution! 👏 Your extensive work on this pull request is truly appreciated. I've reviewed the changes, and everything looks fantastic to me. Your effort is a significant boost to the project.

Thanks again for your time and dedication!