security-group show: fix empty response if an API endpoint is misbehaving

[tgrondier]

Description

exo compute security-group show iterates through all zones to retrieve instances associated with it. If a single API endpoint happened to throw an error, the call itself would error out. This fix allows showing that security group while still showing an error

Checklist

(For exoscale contributors)

• Changelog updated (under Unreleased block)
• Testing

Testing

➜  ~/exo/cli git:(tgrondier/sc-114869/exo-c-sh-show-error-in-preprod) ✗ go run . c sg show edc0d129-2f94-4531-920e-7cf798439cd3                                                                                             25-01-06 16:40 
error while listing instances in security group: 1 error occurred:
        * Get "https://ppapi-at-vie-2.exoscale.com/v2/instance": dial tcp: lookup ppapi-at-vie-2.exoscale.com on 127.0.0.53:53: server misbehaving

┼──────────────────┼─────────────────────────────────────────────────────────────────────────────────────────────────────────────────┼
│  SECURITY GROUP  │                                                                                                                 │
┼──────────────────┼─────────────────────────────────────────────────────────────────────────────────────────────────────────────────┼
│ ID               │ edc0d129-2f94-4531-920e-7cf798439cd3                                                                            │
│ Name             │ default                                                                                                         │
│ Description      │ Default Security Group                                                                                          │
│ Ingress Rules    │                                                                                                                 │
│                  │   08798387-0c7d-4601-a5ed-93367b889314      TCP   0.0.0.0/0   22                                                │
│                  │                                                                                                                 │
│ Egress Rules     │ -                                                                                                               │
│ External Sources │ -                                                                                                               │
│ Instances        │                                                                                                                 │
│                  │   VM-ec365352-f303-4fac-9cad-26e4a63b2227   ec365352-f303-4fac-9cad-26e4a63b2227   159.100.241.234   ch-gva-2   │
│                  │   VM-79e75e58-34c8-4f99-8168-e37722eb97cc   79e75e58-34c8-4f99-8168-e37722eb97cc   85.217.161.242    ch-gva-2   │
│                  │   VM-33e1fdda-d1d4-4fbd-8c7a-4e49971e3975   33e1fdda-d1d4-4fbd-8c7a-4e49971e3975   85.217.161.235    ch-gva-2   │
│                  │                                                                                                                 │
┼──────────────────┼─────────────────────────────────────────────────────────────────────────────────────────────────────────────────┼