Pass unit tests on both PHP 7 and 8

[ZanyMonk]

• [x] Update Docker container
  • [x] Install Sury's PHP repositories
  • [x] Install both PHP 7.4 and 8.2 (FPM)
  • [x] Add Apache config to handle *.phar files with PHP 8.2
  • [x] Update entrypoint.sh to generate agent.php (for 7.4) and agent.phar (for 8.2)
  • [x] Update run.sh to process all tests for the two generated agents
• [x] Fix file_tar module
  • [x] Remove EasyTar.class
  • [x] Reimplement module using native Phar object (available since 5.3)
• [x] Fix sql_console module
• [x] Add printed info in unittest base class to show what PHP version a failing test was running on

[ZanyMonk]

Fixes #167