Implement dynamic selection of parent prefix from a set of custom fields

[henrybear327]

What would you like to be added?

Currently, the parent prefix can only be defined from the ParentPrefix field in the CRD.

We would like to extend it such that we can also use the parentPrefixSelector to obtain the parent prefix and perform prefix claims.

The added selector may look something like this

parentPrefixSelector:
    customFieldX: asdf
    customFieldY: wxyz
    customFieldZ: true

Why is this needed?

Adding more flexibility for specifying the parent prefix, as we can pass it in by name (e.g. custom fields) instead of hard-coded values.