Use separate maps for selector/regular labels

[akalenyu]

What this PR does / why we need it:
This bit us at kubevirt/kubevirt-migration-operator#85

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 #

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• Community: Announcement to kubevirt-dev was considered

Release note:

NONE

[akalenyu]

/approve

[akalenyu]

/approve cancel

[kubevirt-prow]

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