Bug fixes and added 'Institution' to Beteiligte

This commit fixes various bugs and adds small new features:

Bug fixes:

• 'Datensatz veröffentlicht am' is now properly shown on each study page
• 'Beteiligte' are now shown in alphabetical order on the study page
• PostgresSQL version is updated to V8.0.0.0

New features:

• DOI and its respective comment is now included in the Excel Output
• 'beteiligte Institutionen' is a new category for the involved people of a study
• 'Primärforschende/PrimaryResearcher' has been renamed to 'Projektmitarbeitende/Project Staff'
• 'Mitarbeiter/Staff' has been removed as a category for the involved staff of the study