Changes from druidfi/mysqldump-php:main

[back-2-95]

NOTE!

• This PR is just here to show all the things changed in the fork
• This not meant to be merged!

src

• All classes are broke down to their own files
• Interfaces for Compress and TypeAdapter classes
• Only mysql code left
• As much type castings as possible: return values for methods, variables
• Removed unused functions
• Codestyle fixes and cleaning up docblocks

PHP

• No support for EOL PHP versions so only ^7.4 || ^8.0
• PHP 7 support will be dropped later this year when it's EOL'ed
• Composer v2 required

Testing

• Tests are now run in Github Actions workflow
• Local test setup with Docker Compose
• Tests are more verbose