Add the --prefix option to scope daemon

[michalbiesek]

Related to #1361.

This will allow to use daemon in following environment:

• in k8s scope daemon can be used as a container in separate pod with proper privileges related to Ebpf code:
• privileges
• mountPath /sys/kernel/debug This is sufficient to handle snapshot file but to retrieve the files generated by the library from other containers/pods we need to have access to /proc view from host.

There is the comment in the code which describes this issue: https://github.com/criblio/appscope/blob/9c9bb65b6f373744682e08e2b0f75f61fc6d8de2/cli/snapshot/snapshot.go#L195-L203

[michalbiesek]

The second thing besides above is after discussion with @jrcheli is when run scope k8s we should ensure that scope daemon should run in every node - this thing can be done I think via https://kubernetes.io/docs/concepts/workloads/controllers/daemonset/