Mac: Change docker project host property

[camtes]

Change variable to host.docker.internal.

[capynet]

Also would be a good idea to deprecate DOCKER_PROJECT_HOST env var since host.docker.internal now seems to be a common host for all platforms. If this is true, just hardcode host.docker.internal intro docker-compose.override.yml and remove the env var.

[capynet]

To test if this works try to debug.