[WIP] add resource limit options to podman exec command

[MayorFaj]

Checklist

Ensure you have completed the following checklist for your pull request to be reviewed:

• Certify you wrote the patch or otherwise have the right to pass it on as an open-source patch by signing all
  commits. (git commit -s). (If needed, use git commit -s --amend). The author email must match
  the sign-off email address. See CONTRIBUTING.md
  for more information.
• Referenced issues using Fixes: #00000 in commit message (if applicable)
• Tests have been added/updated (or no tests are needed)
• Documentation has been updated (or no documentation changes are needed)
• All commits pass make validatepr (format/lint checks)
• Release note entered in the section below (or None if no user-facing changes)

Does this PR introduce a user-facing change?

Add resource limit options (--cpus, --memory, --cpu-shares, --cpuset-cpus, --cpuset-mems, --memory-swap) to podman exec command. Requires OCI runtime support (crun >= 1.9 or runc >= 1.2).

Changes

• Added CLI flags: --cpus, --memory, --cpu-shares, --cpuset-cpus, --cpuset-mems, --memory-swap
• Implemented resource limit parsing and cgroup creation for exec sessions
• Added integration and system tests with runtime support detection
• Updated man page documentation

Requirements

• Requires OCI runtime support: crun >= 1.9 or runc >= 1.2
• Resource limits create a temporary sub-cgroup for the exec session

Testing

podman run -d --name test alpine top
podman exec --cpus=0.5 --memory=256m test stress-ng --vm 1 --vm-bytes 200M

fixes #26875

[packit-as-a-service]

[NON-BLOCKING] Packit jobs failed. @containers/packit-build please check. Everyone else, feel free to ignore.

[giuseppe]

How is it supposed to work on cgroup v2?

There can't be processes in a parent cgroup, so you'll first need to move all the processes to a sub-cgroup.

[giuseppe]

the OCI runtimes do not have any support for exec and cgroups limits, so this is wrong