Add containerd option for registry mirrors

[hakman]

This simplifies the way containerd options can be added, using pelletier/go-toml.
Next step for 1.20 would be to move config generation to NodeUp.

/cc @olemarkus @zetaab
@bharath-123

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

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[olemarkus]

/hold for more comments if necessary
/lgtm

[bharath-12345]

looks good. I ll rework my PR to default systemd as a cgroup-driver to use this toml library. Thanks for doing this!

[rifelpet]

can you use the field in an integration test so we can confirm the expected output?

[hakman]

can you use the field in an integration test so we can confirm the expected output?

Sounds good to me. Done.

[hakman]

Seems like it's ready now. Thanks everyone :).
/hold cancel

[olemarkus]

/lgtm

[hakman]

Thanks @olemarkus