`odo preference add registry` should add registries to the beginning of the list

[rm3l]

Originally posted by @rm3l in https://github.com/redhat-developer/odo/issues/6205#issuecomment-1273419534

Discussed the possibility to make odo preference add registry insert new entries at the beginning of the list, but this would be a breaking change for users with existing preferences. However, breaking changes could ideally be handled using the apiVersion field that we already have in the preferences file.

See https://github.com/redhat-developer/odo/issues/6205 for more context.