imp(testkit): integration test for packet timeout

[rnbguy]

Closes: #398 Closes: #1217

Description

Integration tests for:

• [x] Packet timeout.
• [x] Packet timeout on channel close.

Also, reproduces the bug from #1217.

The latest branch from basecoin-rs now has non-membership proofs for its IAVL tree.

This PR adds a packet timeout scenario to our existing integration test. This exercises non-membership proof for the Tendermint light client.

---

PR author checklist:

• [x] Added changelog entry, using unclog.
• [x] Added tests.
• [x] 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).

[rnbguy]

Let's merge this only after informalsystems/basecoin-rs#141 is merged.

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 98.22695% with 5 lines in your changes are missing coverage. Please review.

Project coverage is 67.31%. Comparing base (4ea4dcb) to head (7787301).

Files	Patch %	Lines
ibc-testkit/src/relayer/integration.rs	93.33%	3 Missing :warning:
ibc-testkit/src/relayer/context.rs	99.38%	1 Missing :warning:
ibc-testkit/src/relayer/utils.rs	98.64%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #1215 +/- ## ========================================== + Coverage 66.34% 67.31% +0.97% ========================================== Files 234 234 Lines 23328 23553 +225 ========================================== + Hits 15477 15855 +378 + Misses 7851 7698 -153 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.