IDAContext defaults to questionable URL for JupyterLab service

src/contexts/IDAContext.js line 12 provides a default URL for JupyterHub services corresponding to the SKAO JupyterHub system.

This URL is over-written in src/components/services/Interactive.js line 36 when the value selected by the user in the dropdown is changed.

If the user never adjusts the dropdown, then the default URL is never over-written. In this case, the Deploy button will redirect the user to the default set in IDAContext.js, regardless of what the service is actually selected in the dropdown.

That's bad enough as it stands, but what if there is only one service configured (e.g., following esap-api-gateway!100? In this case, the value which appears in the dropdown never changes (because there is nothing else to select), so if the default doesn't happen to match the only service configured then there's no way for the user to override it.