feat: return proper error if boltInfo is empty

[kmushegi]

What it Does

Check if boltInfo is empty (this can happen when Quicksilver is down or returning nothing) and return an appropriate error.

Previously this was bubbling up as

level":"ERROR","ts":"2023-07-25:23:28:22.188","caller":"api/api.go:62","msg":"internal error","request_id":"hPbxEnzHaa_1oUrWq9VqMbfmCL0","user_agent":"Boto3/1.28.5 md/Botocore#1.31.5 ua/2.0 os/linux#4.14.318-241.531.amzn2.x86_64 md/arch#x86_64 lang/python#3.7.16 md/pyimpl#CPython cfg/retry-mode#legacy Botocore/1.31.5","error":"could not cast availableEndpoints to []string"}

and now the error log printed is

{"level":"ERROR","ts":"2023-07-26:01:08:21.203","caller":"api/api.go:62","msg":"internal error","request_id":"KLPqhpH1UAno6dcGkULV-ArSpPM","user_agent":"aws-cli/2.9.19 Python/3.9.16 Linux/6.1.34-59.116.amzn2023.x86_64 source/x86_64.amzn.2023 prompt/off command/s3api.get-object","error":"boltInfo is empty"}

[cv-projectn]

This means QuickSilver is unavailable. Should we redirect to S3?

[kmushegi]

This means QuickSilver is unavailable. Should we redirect to S3?

Let's go one step at a time, not straightforward at the moment to redirect to s3 rn.