Fix signature mismatch by sorting query parameters

[cpick]

https://cloud.google.com/storage/docs/authentication/canonical-requests#about-query-strings

The parameters in the query string must be sorted by name using a
lexicographical sort by code point value.

Fixes #298

[cpick]

A simpler option that I had tested locally would be to just change query_parameter from a HashMap into a BTreeMap. This would require fewer allocations, but would be an API-breaking change and would still generate a signature mismatch if a user included a key that sorted lexicographically lower than "X-Goog-SignedHeaders" in query_parameters.

[yoshidan]

Thanks!