If API returns an error, report it to the user

[jamesamcl]

Currently the frontend does not report any errors to the user.

[tskir]

I stumbled into this when trying to create a project. The API returns "403 Attempt to create a project by a non-super user: [email protected]"; however, this is not reported in the front-end and gives the impression that the "Create project" button simply doesn't work