CORE-5832 App dates now Date types.

Updated App endpoints to use Date types instead of Long type timestamps.
CORE-5386 Added validation_rule_arguments.ordering.

Added an ordering column to the validation_rule_arguments table (copied from the old hid column).
Added a default value to the parameters table's ordering column.
CORE-5832 Added PUT /apps/:id App update endpoint.

Removed obsolete App import and update endpoints and docs.
CORE-5832 Refactored app-metadata/get-app.

Refactored metadactyl.persistence.app-metadata/get-full-app into the get-app function.
CORE-5832 Fix compilation error.

Replaced a Java UUID call with a kameleon.uuids/uuid call instead.