cmd/go: check that expected Origin fields are present to reuse module info
When 'go list' or 'go mod download' uses a proxy to resolve a version
query like "@latest", it may have origin metadata about the resolved
version but not about the inputs that would be needed to resolve the
same query without using the proxy.
We shouldn't just redact the incomplete information, because it might
be useful independent of the -reuse flag. Instead, we examine the
query to decide which origin information it ought to need, and avoid
reusing it if that information isn't included.