Read sumo assets list from Sumo API

At the moment we are reading the Sumo assets list from a hardcoded list stored in a json file in the repo. This file is maintained is manually maintained by the Sudo team. This was made as a temporary work around for the first iteration of FMU Settings.

The long term goal is to read this asset list (only returning the assets the users have access to) from Sumo API. The framework for it is there in the code, it just needs to read it from Sumo API and not from the json file.

This issues covers implementing this change.

Before starting to implement we should make a plan for how we want to deal with authentication towards Sumo API.

Start by locating the JSON asset-list reader and the existing Sumo API framework described in the issue, then review how authentication should be handled. Done means the asset list comes from Sumo API, includes only assets the user can access, and no longer depends on the manually maintained repository JSON file.

Written by the indexing model from the issue text.