We should output a simple error message in the UI via the following fields (for example):
inflight.response.details.subnet-061df2bf65465533a

.egress_url_errors-[0-n]
.generic_error-[0-n]
.verifier_unknown-[0-n]

Ex: details.subnet-061df2bf65465533a.egress_url_errors-0 = "egressURL error: quay.io:443"
An example error message we could show in the UI would be:
"subnet-061df2bf65465533a encountered an egress url error attempting to access 'quay.io:443'"
Implementation Notes:

There can be 1-n subnets!
There can be 1-n errors per subnet!
UI should show the first 4-5 error messages and put any remainder in a 'more...' expandable section.