Improved ITkPD authentification

At the moment localDB authenticate once to PDB and then reuse the same credentials whenever these are needed, e.g. when uploading data to the PDB.

This is an issue for us as we share the localDB (docker swarm) service among the three institutes of the Paris cluster.

This MR attempts to fix this by checking bef. each PDB upload if the authenticated localDB user institute matches the current PDB authenticated user institute. If it does not then it uses the 2 PDB codes that the user systematically provides before an upload to PDB to reauthenticate on PDB with the user so that the correct institute is considered for the uploaded tests.

Currently being tested by the Paris cluster and no issue so far.