Signed URLs with parameters

[lubitchv]

External tools now work with signed urls. But as it is presently implemented it limits the use of Dataverse APIs by external tool, for example, use of apis with parameters. At present, the only parameters that are allowed are those declared in manifest json in queryParameters such as fileid, datasetid, etc. But sometimes the tool needs input from a user to use a proper api, for example it needs data for a specific variable selected by the user, for example http://localhost:8080/api/access/datafile/22/?format=subset&variables=v178 where v178 is a parameter selected by the user. We used this type of API for Data Curation Tool. Currently this api cannot be used by external tool. It would be nice to have a mechanism that would support parameters for signed urls.