Full implementation of multi-arch support in a devfile registry

[elsony]

Which area this feature is related to?
/area api

Which functionality do you think we should add?

Provide the full implementation of multi-arch support in a devfile registry

Why is this needed? Is your feature request related to a problem?
The current approach requires a stack to create multiple entries in a devfile registry with different stack names in order to provide multi-arch support.

Detailed description:
The first pass of the multi-arch support provides a simple approach to handle a stack with multi-arch support was implemented as part of #244 (comment). In the recent devfile cabal discussion (https://docs.google.com/document/d/1Zn6D1gNu1gDidtillni0hNAeU5pscfqwhx4mv3MmmwY/edit?pli=1#heading=h.66t07559x013). It has been decided to do the full implementation in order to avoid a stack creating multiple entries of the devfile in a devfile registry to support multi-arch scenario.

Describe the solution you'd like

Implement case #1 in https://docs.google.com/document/d/1MTgxy2EAFYqvN7Twtbr_iWlG9xsghOyI89RRILxvsqY/edit#heading=h.esvxv0e8cpjx

Describe alternatives you've considered

See detailed description

Additional context

[thepetk]

I think this is completed from after EPIC #1608