integrations/operator: Add openSSH and openSSHEICE servers

[hugoShaka]

Fixes: #36839

This PR adds OpenSSH and OpenSSHEICE support to the operator through two new resources:

• TeleportOpensshServer
• TeleportOpensshEICEServer

Notes about the 1 resource vs many resources for the subkinds:

• teleport, openssh, and openssh-aws-eice subkinds are backed by the same resource
• the operator must not manage the teleport subkind
• there is no Kubernetes-friendly way to pass a subkind, putting it in the spec would break the unmarshalling

changelog: Add OpensshServer and OpensshEICEServer support in the operator

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[public-teleport-github-review-bot]

@hugoShaka - this PR will require admin approval to merge due to its size. Consider breaking it up into a series smaller changes.

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[tigrato]

should we make this property mandatory or should we leave it to teleport?
This is a situation where validation hooks would be great

[hugoShaka]

I think teleport should reject an invalid value and we should keep the CRD validation to the minimum: enforcing a sane data structure.

[public-teleport-github-review-bot]

@hugoShaka See the table below for backport results.

Branch	Result
branch/v15	Create PR