Fix panic when querying connections filtered by counterparty chain

[romac]

Closes: #3380

Description

---

PR author checklist:

• Added changelog entry, using unclog.
• Added tests: integration (for Hermes) or unit/mock tests (for modules).
• Linked to GitHub issue.
• Updated code comments and documentation (e.g., docs/).
• Tagged one reviewer who will be the one responsible for shepherding this PR.

Reviewer checklist:

• Reviewed Files changed in the GitHub PR explorer.
• Manually tested (in case integration/unit/mock tests are absent).

[romac]

With this branch, the results from following the steps at #3380 (comment) are as expected:

Query all the connections on ibc-0:

$ hermes query connections --chain-id ibc-0
SUCCESS [
    ConnectionId(
        "connection-0",
    ),
    ConnectionId(
        "connection-1",
    ),
    ConnectionId(
        "connection-2",
    ),
    ConnectionId(
        "connection-3",
    ),
    ConnectionId(
        "connection-4",
    ),
    ConnectionId(
        "connection-5",
    ),
]

Then filter the connections to only include the ones who point to ibc-1:

❯ hermes query connections --chain ibc-0 --counterparty-chain ibc-1
SUCCESS [
    ConnectionId(
        "connection-0",
    ),
    ConnectionId(
        "connection-1",
    ),
    ConnectionId(
        "connection-2",
    ),
]

Let's do the same for the connections pointing to ibc-2:

$ hermes query connections --chain ibc-0 --counterparty-chain ibc-2
SUCCESS [
    ConnectionId(
        "connection-3",
    ),
    ConnectionId(
        "connection-4",
    ),
    ConnectionId(
        "connection-5",
    ),
]

[ancazamfir]

lgtm, thanks @romac

[ancazamfir]

lgtm, thanks @romac