vSphere: Remove tag-based handling for multiple machines with the same name

[alvaroaleman]

What this PR does / why we need it:

• Removes the tag-based handling for multiple machines with the same name, as vsphere doesn't seem to support that anyways, seen e.G. in vSphere - PoweredOff VMs cannot be reconciled #636
• Replaces the tag-based marker used to indicate if creation was successful with a wrapper around the Create that will call Cleanup if there was an error. This is backwards-compatible (using an annotation or sth would result in all vsphere machines prior to this change getting re-created), more intuitive (no-one expects a function called GET to mutate things) and removes the need for the machine-controller to have permissions to manage tags

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Fixes #

Special notes for your reviewer:

none

[kdomanski]

/lgtm
/approve

[kubermatic-bot]

LGTM label has been added.

Git tree hash: 0a898322aa8e423e27a7d9f3f4889090aba4e2c5

[kubermatic-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: alvaroaleman, kdomanski

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