CE Phase 3: Self-hosted Collaboration Engine server.

[Peppe]

As a developer
I want to be able to deploy Collaboration Engine as a separate server in my intranet
So that my Vaadin application can contact it and work in a clustered deployment environment

Acceptance criteria

• Collaboration Engine can be deployed into an own intranet server as a self-contained jar.
• A Vaadin application can contact a Collaboration Engine over the network
• All Collaboration Engine features of phase 1 should still work with the separate server.
• Only authorized application servers can contact the CE server

General criteria

remember to remove those that are not applicable

• APIs reviewed [here link to API review documentation, if any]
• Performance [here link to the requirement or tests, if any]
• UX/DX tests in Alpha [here link(s) to issue(s) with the description of UX/DX tests, if any]
• Design [here link to e.g. issue with design specification, a mockup, Figma specs]

Do NOT use these just yet

Under constrution (would be used instead of User Value document - in the 2nd iteration of the template):

• Documentation: [here link to the documentation]
• How to test? [here link to the GH issue or some external document with the test scenario]
• Limitations: [here list of limitations, preferably links to GH issues]

[Peppe]

Closing as duplicate of #1988