feat: add cgroup setter node

[TetsuKawa]

Description

This PR adds cgroup setter node which attach processes to your custom cgroup.

Related links

Tests performed

• Confirmed that this node attach processes to some custom cgroups.
• Confirmed that this node output error logs when it fail to write attach processes to a cgroup, pgrep fail to find a pid, or the config file is wrong.
• Confirmed that this node publish proper /diagnostics.

Notes for reviewers

Assumptions, Write permission is required for a custom cgroup, and /sys/fs/cgroup/cgroup.procs to attach a PID to the cgroup.

Interface changes

ROS Topic Changes

ROS Parameter Changes

Effects on system behavior

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