Add sorting options for listing changes when available

[mderka]

Currently, the service API allows for only one sorting key which is the change sequence (time of the changes being received by the server). When more sorting options become available, they should be implement.

[garrettjonesgoogle]

This is a speculative issue for API options that may or might not exist in the future; I feel like we should only file issues for work we know needs to be done. Closing this out.