Implemented LXC as Executor

What does this MR do?

It add LXC as an Executor

Why was this MR needed?

LXC is a virtualization method based on containers which shows great potential as a build environment allowing concurrent builds and the discarding of changes made at build time.

Are there points in the code the reviewer needs to double check?

The Main Functionality of using LXC under different Operating Systems

Does this MR meet the acceptance criteria?

  • Documentation created/updated
  • Tests
    • Added for this feature/bug
    • All builds are passing
  • Branch has no merge conflicts with master (if you do - rebase it please)

What are the relevant issue numbers?