Key module integration

Problem/Motivation

Improve security and flexibility by integration with Key module.

Proposed resolution

Move confidential client data from annotations to Key data or core key/value storage.

Remaining tasks

• Key provider service to return the client data from the relevant storage system.
• Provide an interface in the admin UI to collect the client data

User interface changes

• Plugin collection listing with edit links
• Client data form

API changes

Move confidential client properties from plugin definition (Annotation) to appropriate storage.