Add capability to run applications that are Charliecloud sqfs format (DockerRequirement) for tasks

[pagrubel]

This should be like the Container use functionality although we don't need to do a convert to tmp space.
However, there may need to be a check that squash fuse is installed. This may already be tested by Charliecloud can we just pass on the error?

Maybe we can put a test that fails in our integration tests and test for the message and then test overnight on our systems that we know have squash fuse.

[pagrubel]

@kchilleri I think using our clamr example would be good, if you could take that container and save a sqfs version of it, to start with.

[kchilleri]

@kchilleri I think using our clamr example would be good, if you could take that container and save a sqfs version of it, to start with.

I will take a look!