lang/php80: Adding MySQL 8.0 'caching_sha2_password' support

• Pet portlint
• Add non-default OPTION MYSQL80

This patch adds an OPTION for adding 'caching_sha2_password' (Default
Password mechanism in MySQL >= 8.0) in php80. If the OPTION MYSQL80 is
selected it will build openssl module with base PHP including mysqlnd.
This will also prevent php80-openssl module from being installed in the
future. php80-mysqli and php80-pdo_mysql will use mysqlnd.

PR: 252420
Reported by: sean@rogue-research.com
Approved by: tz
Sponsored by: Bounce Experts
Differential Revision: https://reviews.freebsd.org/D29491