PHP 8.1 & Coding style & Production build

minimum supported PHP version is now 8.1
improved coding style
- new Php-Cs-Fixer config (lowercase true/false/null, four spaces instead of tabs, imports ordering etc.)
- removed unnecessary phpdoc comments
- replaced typed array syntax from x[] to array<x> in phpdoc comments
- promoted constructor properties
replaced development docker images with the new unit and cli images from 68publishers/php
added production docker images build. Both commands outputs two images - 68publishers/cmp:app-<version> and 68publishers/cmp:worker-<version>
- $ make build.local.<version> - stores images locally
- $ make build.multiarch.<version> - builds images for AMD and ARM architectures and pushes them to the DockerHub repository

68publishers / consent-management-platform