Make apt installed FogROS2 work without copy in project

[jeffi]

Describe the bug
If you apt install FogROS2, but do not include a copy of FogROS2 in your workspace, it will fail to start the cloud side. The fix could be as simple as adding:

    self.apt_install(f"ros-{self.ros_distro}-fogros2")

to cloud_instance.py. However, we may have to do additional checks--e.g., to prefer FogROS2 that is part of the workspace when present.

To Reproduce

1. apt install ros-humble-fogros2
2. create workspace and simple example application (e.g., talker)
3. launch with 1 node in the cloud.

Expected behavior
Cloud starts up.