storage: assert on Replica state on creation
storage: assert on Replica state on creation

This would catch any spurious manipulation of Replica state in the
constructor.

cockroachdb/cockroach,petermattis/cockroach,petermattis/cockroach,petermattis/cockroach,cockroachdb/cockroach,cockroachdb/cockroach,vaibhavarora/cockroach,paperstreet/cockroach,arjun4084346/cockroach,cockroachdb/cockroach,glycerine/cockroach,maxlang/cockroach,veteranlu/cockroach,vivekmenezes/cockroach,glycerine/cockroach,petermattis/cockroach,arjun4084346/cockroach,petermattis/cockroach,cockroachdb/cockroach,maxlang/cockroach,veteranlu/cockroach,maxlang/cockroach,vaibhavarora/cockroach,sunya123/cockroach,glycerine/cockroach,arjun4084346/cockroach,veteranlu/cockroach,vaibhavarora/cockroach,vaibhavarora/cockroach,vivekmenezes/cockroach,vaibhavarora/cockroach,paperstreet/cockroach,arjun4084346/cockroach,vivekmenezes/cockroach,arjun4084346/cockroach,arjun4084346/cockroach,veteranlu/cockroach,paperstreet/cockroach,cockroachdb/cockroach,veteranlu/cockroach,paperstreet/cockroach,sunya123/cockroach,petermattis/cockroach,sunya123/cockroach,vivekmenezes/cockroach,paperstreet/cockroach,glycerine/cockroach,maxlang/cockroach,glycerine/cockroach,veteranlu/cockroach,glycerine/cockroach,maxlang/cockroach,veteranlu/cockroach,maxlang/cockroach,sunya123/cockroach,paperstreet/cockroach,paperstreet/cockroach,petermattis/cockroach,vaibhavarora/cockroach,maxlang/cockroach,cockroachdb/cockroach,vivekmenezes/cockroach,sunya123/cockroach,vivekmenezes/cockroach,petermattis/cockroach,vivekmenezes/cockroach,vaibhavarora/cockroach,veteranlu/cockroach,glycerine/cockroach,maxlang/cockroach,sunya123/cockroach,arjun4084346/cockroach,sunya123/cockroach,glycerine/cockroach,sunya123/cockroach,paperstreet/cockroach,vivekmenezes/cockroach,cockroachdb/cockroach,vaibhavarora/cockroach,arjun4084346/cockroach