Apply "ON DELETE CASCADE" rule to all existing foreign key references where it's missing

Purpose/Overview:

Apply "ON DELETE CASCADE" rule to all existing foreign key references where it's missing

Requirements/Scope:

1. current set of DB scripts should be reviewed and the rule applied where it's not present for FKs

Acceptance criteria:

• All FKs have ON DELETE CASCADE
• It should be possible to remove parent entity (like Central Server) even if it has referenced data