fix(apollo-react-relay-duct-tape): use correct id for compiler fragment, add check for partial result

[sjwilczynski]

The aim of this PR is to fix an issue discovered while integrating refetchable fragments for Jana in TMP. In scope of this PR we:

• make sure that if there is an id variable on the query, it doesn't override the id used on the compiled fragment (reordering of spread and id in useCompiledFragment)
• add one more invariant, checking if observableQuery returned partial result (and failing in such case)
• add another invariant in case of data returned being null
• update readme about cache configuration