when describing FK relationships using JDBC we need to include the available schema to filter the results.

make use or the :report-timezone in the newly applied query :settings instead of having lots of different code look up the value itself.  update a few unit tests to account for the fact that query results are now converting temporal values to strings.

use our new ->ISO8601DateTime protocol to simplify things a bit and create unit tests specifically for our new QP middleware functions.

update our revert-to-revision protocol function to require passing in a user-id which is necessary for most entities and add revision/revert endpoints onto our dashboard api with unit tests.

update the functions for reverting a dashboard so that it handles restoring DashboardCardSeries now.

update implementations for serialize-dashboard and diff-dashboard to account for the addition of :series on DashboardCards.

when no field-values exist for a field, clear out any previous field-values so we don't leave stale data lying around.

apply a check for `valid-metadata?` when updating the attributes of a Field so that we can prevent invalid metadata configurations (#824)