Add endpoint to fmu-settings-api for recording UI events

To be able to log different events of interest from the GUI, we should create a new endpoint in the API for recording such UI events.

The endpoint should receive the event as part of the request and log it Azure so that we can create dashboards monitoring these UI events.

Start by locating the API endpoint definitions and the existing Azure logging integration in fmu-settings-api. Define how the request carries a UI event and confirm that the event is recorded in Azure in a form suitable for dashboards; done means the endpoint accepts an event and its Azure log entry can be monitored.

Written by the indexing model from the issue text.