Proposal: Add the ability to mount remote SMB volumes in devcontainer

[PALuczak]

Currently, in order to mount SMB share in the devcontainer, it must be first mounted on the host machine. This limits the portability of the configuration, as whenever we move the devcontainer between machines, we must remember to also mount the remote volumes, which is especially problematic in cloud environaments.

It would be very useful if the "mount" section of the devcontainer.json supported the creation of CIFS/Samba volumes associated with the devcontainer. Docker already has this capability, which means that adding this feature should only require supporting the necessary option syntax in devcontainer.json.