Honor Preservation for any update strategy

[defo89]

How to categorize this issue?

/area ops-productivity
/area control-plane
/kind enhancement
/priority 3

What would you like to be added:

This is a follow up to #1008 - We would like MCM to honor node.machine.sapcloud.io/preserve-when-failed=true Node annotation regardless of the update strategy.

Why is this needed:

As a baremetal server operator I would like to perform server maintenances on nodes:

• Set Node annotation node.machine.sapcloud.io/preserve-when-failed=true
• Power off the underlying server for maintenance work (e.g. RAM replacement)
• During this process Node will be NotReady, Machine transitions to Failed phase
• Shoot reconciliation should be not affected
• After performing the maintenance annotation node.machine.sapcloud.io/preserve-when-failed=true is removed, server is powered on, Node is Ready and Machine transitions back to Running

[defo89]

cc @hardikdr