Azure function hosting and scale

[tba76]

Description

Consider using Azure Functions Premium Plan instead of App Service Plan (dedicated plan).
https://learn.microsoft.com/en-us/azure/azure-functions/functions-premium-plan?tabs=portal

Automatic scaling by queue-length and age of the oldest message
https://learn.microsoft.com/en-us/azure/azure-functions/event-driven-scaling

Always ready instances and pre-warmed instances.
Faster upscale.

https://sahangunathilaka.medium.com/how-to-select-the-most-suitable-hosting-plan-for-azure-function-app-deployment-8896f0a63a6a
https://www.javatpoint.com/what-is-microsoft-azure-functions-premium-plan

Additional Information

The current FileScan application, its queue and function might replaced by a solution using Defender. The priority should be to look into that change rather than to build on the current solution. We're leaving this issue in case we run into performance issues.

Tasks

No response

Acceptance Criterias

No response

[olebhansen]

Awaiting findings in #156