feat: allow configuring namespaced kernel parameters (sysctls) for a promotion stage (#160)

Description

• add a new section sysctls to physicalSnapshot parameters
• validate sysctl names https://docs.docker.com/engine/reference/commandline/run/#configure-namespaced-kernel-parameters-sysctls-at-runtime
• apply configured sysctls to promotion container

Related issue

#160 (closed)

Examples

...
    physicalSnapshot:
      options:
        sysctls:
          kernel.sem: "250 32000 32 128"
          kernel.shm_rmid_forced: "test"
          fs.mqueue.john: "test"
        ...

Checklist

• the MR description has been reviewed
• this MR contains text changes and they have been reviewed OR there are no texts changes
• this MR contains GUI/CLI changes and they have been reviewed OR there are no GUI/CLI changes
• this MR contains API changes, specifications reflect those changes and they have been reviewed OR there are no API changes

Closes #160 (closed)