Support building in container for Cmake projects

[ghentschke]

Especially for cross-platform development it is very helpful to build C/C++ projects in a container. If the dockerfile is part of the project, this project can be easily shared and build on every machine without the need to setup the build environment.

The container build is currently only available for managed projects. It would be great to support cmake projects as well.

The next step would be to run the C/C++ language server for the LSP based C/C++ Editor in the docker/podman container as well. That would require this change #813 in LSP4E

@jjohnstn WDYT?