WorkflowArchive support rotating DB passwords

# Summary

For security reasons we have a rotating DB password - this means our DB password changes every day.
In the source code, I could see the WorkflowArchive in initiated with a password on the server initialization.
This means, we need to restart the service on every password change.
A better solution would involve having the Argo WorkflowArchive retrieve the db password secret before the use of the DB connection or having an API for restarting the DB session

# Use Cases

On every DB password change

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**Message from the maintainers**:

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Start by locating WorkflowArchive initialization and its database connection lifecycle; the issue does not name files or tests. Determine how the rotating database secret can be used without restarting the service, and define validation showing that a password change is handled during normal operation.

Written by the indexing model from the issue text.