Open Project styling sync improvements

[trrenty]

We should consider the following and see if we can come up with solutions.

1. When the job executes it can only run with the rights of a customizable user. We can't set it to run as "superadmin" because we need a user that has connected to the OpenProject instances. In order to address this, I created a listener that reacts to the creation of new OpenProject instance configurations. When this happens, the user that created the configuration is set as the job user. If the user is never authorized to OP the styles might never update. Maybe we can find a solution to this.
2. Currently, the sync job is only run at the scheduled time or if the user triggers it manually. It would be nice to somehow trigger it after a configuration is added. In order to do this, we need to force the user that added a OP instance to get authorized in OP and then trigger the job. Alternatively, we could somehow detect when a user get authorized to OP and then trigger the job - this would be worse because potentially many users might get authorized and we would need to check whether the job was run or not everytime.