OCS API to send a message

[ChristophWurst]

Is your feature request related to a problem? Please describe.

As a Nextcloud developer I want to automate processes and trigger emails. Right now there is no way to integrate with this app.

Describe the solution you'd like

Add an OCS endpoint to send a message.

Outbox is where we're going to add these messages.

Only create is needed for now.

Work packages

• [ ] API
• [ ] API docs

Describe alternatives you've considered

N/a

Additional context

Deliver automation and workflow capabilities across the product suite