Validate against directory traversal for arguments

[lumjjb]

Check if it is possible to perform directory traversal attacks against the runtime and protect against them if possible.

Where this may come up is in the specifying of the .nabla file being specified when passed to runnc-cont/nabla-run.

[lumjjb]

test it by creating a simple container that’s like

FROM bt/nabla-node-base
ENTRYPOINT ["../../../../../../some.nabla"] or ENTRYPOINT["/some.nabla"]

and have the some.nabla be somewhere in the host file system
so the solution would to ensure that ENTRYPOINT resolves to it’s own root
so like ../../some.nabla should resolve to /some.nabla before setting the nabla launch path to container_rootfs/ENTRYPOINT

[hiteshkotian]

Working on this