Add sharding key tracking issues for feature category `secrets_management`.

## Background

These tables were unable to be classified automatically, and will require manual input. Eventually all tables will
need to be correctly classified, but we understand that this will be complex for some tables and completing these
will take time. Instead, our goal for this task is to ensure all remaining tables are tracked in an issue, and to
classify any straightforward cases that our automation may have missed (options 1 and 2 below).

We have assigned a random backend engineer from ~"group::pipeline security" as the initial DRI for this task, as well as an
engineering manager for visibility. Please note that we are not requesting a large time commitment, creating one
issue and linking it for all tables is perfectly acceptable.

When you are finished, please assign to the ~database reviewer/maintainer suggested by Danger.

If you have any questions or c...