Add Default Error Message in Cases Where there are No Itins

[amy-corson-ibigroup]

Description:

Adds a default OTP-style error message encouraging a user to change their search if we are returning a blank itinerary results pane.

PR Checklist:

• [ ] Does the code follow accessibility standards (WCAG 2.1 AA Compliant)?
• [ ] Are all languages supported (Internationalization/Localization)?
• [ ] Are appropriate Typescript types implemented?

[amy-corson-ibigroup]

@miles-grant-ibigroup We can add this to the error set in cases where the we actually return a response from the server! The issue is when the query is invalid (such as when a user only selects "rental" in the mode selector), we don't actually dispatch the routing request, and so there's no error set to add to.

[miles-grant-ibigroup]

@miles-grant-ibigroup We can add this to the error set in cases where the we actually return a response from the server! The issue is when the query is invalid (such as when a user only selects "rental" in the mode selector), we don't actually dispatch the routing request, and so there's no error set to add to.

That makes sense. But it definitely has to be added somewhere in the routing request process rather than at render time. What we have now is not ok