Dpisek/group level dependencies enhance error message

Instead of always displaying a generic error message, hardcoded on the frontend, we should make use of the backend's error message when anything goes wrong with fetching the group-level dependency list.

For example, there is currently a limitation on the number of projects that can be selected for filtering. If the user selects more than the limit, an error is shown. Currently, we only display a very generic message and ask the user to check their network connection:

Before	After

Related to #438354 (closed)