Create new PHP images

[jelen07]

Why

We are currently building production images in the client's infrastructure. We would like to shift this responsibility to our side and deliver already completed images with the application.
These should be the default base images.

Specification

1. PHP CLI -> prod + dev
2. PHP with a webserver (NGINX vs NGINX Unit) -> prod + dev
3. PHP 7.4 and 8.1 are also ARM-compatible (Apple M1, M2 chips)
4. Use Makefile to build and push
5. Use GitHub actions to automate the release/workflow to push new tags/images
6. Some PHP extensions can be installed conditionally with Imagick, Xdebug, Composer, etc. Let's first discuss what each image should contain. It can be one Dockerfile per PHP version that will run with multiple parameters during the build, etc.
7. Testing project 👉 https://github.com/68publishers/consent-management-platform
8. It's good to keep in mind that the client running the application in k8s, AWS, azure, etc.

Other

1. Repository -> https://github.com/68publishers/docker
2. Registry -> https://hub.docker.com/repository/docker/68publishers/php/general
   Unfortunately, they are going to charge for the basic plan for organizations, so we have to figure out where to take them

We currently overuse tags for different versions of docker images. It might be worth figuring out how to do it better if we find this to be a problem - 68publishers/php:8.1-unit-dev-1.0.0 vs 68publishers/php-8.1-unit-dev:1.0.0.

Follow-up issues

1. Allow to use HTTPS on local environment #2
2. Separate build of front-end assets to the standalone image #3