Pid at ufz - improvements
Changes:
- add handling for null values for manufacturer names before adding the non null constraint in the database.
- set persistent identifier in schemas to readonly
- switch pid_prefix and pid_suffix
- add update functionality for the PIDINST data if there is a change on our instruments & or their contacts
- some refactoring to have the pidinst updates as mixin classes, as well as pid deletion.
Edited by Nils Brinckmann