When deleting a connection, update the status as part of the API

[gosusnp]

What

When we delete a connection, we change the status of the connection as part of the workflow.
It means that we currently do know exactly when we are effectively deleting the connection which also causes issues in our acceptance tests.

How

In our delete endpoint:

• signal the workflow for deletion as we do today
• update the db to mark the connection as deleted before returning from the API rather than wait for the workflow to do it.

[benmoriceau]

Once done, we need to revert #18932