Fix query-param handling on the client side

[argouber]

There are scenarios where the annotations are ignored when the client thrift actually specifies it.
Similarly on the endpoint thrift, handling had some bugs

• Optional query param is the only item present in the struct and has an annotation that does not include the struct field's name. We do not handle this correctly.

[coveralls]

Coverage increased (+0.06%) to 67.841% when pulling 5e8c7dd on argo/qparam_fixes into f018151 on master.