AbstractService: Replace mcrypt_encrypt/decrypt calls with their openssl counterparts

[xplodwild]

In AbstractService.php around line 677 to 733, the methods mcrypt_encrypt and mcrypt_decrypt are deprecated.

The mcrypt PHP module is deprecated as of PHP 7.1 and will be removed in PHP 7.2. See the PHP 7.1 deprecation article for more information. The mcrypt library has been in an abandoned state for over a decade, and thus might present security issues in the future.

It is advised to use the OpenSSL equivalent, openssl_encrypt and openssl_decrypt.

[eurodude]

This is an interesting task as the chosen algorithm is not mappable to openssl algortithm (MCRYPT_RIJNDAEL_256). So all the data exported will not be compatible with the new version.

However, importing in the old version of a file, then upgrading MONARC, then exporting again should work fine to "port" the files.

[eurodude]

The issue has been resolved