fix: audit fixes

[oren-lava]

Description

Closes: #XXXX

In this PR I fixed a few issues that came up during an audit of the consensus code.

1. Added a warning comment on proper use of DetectionIndex()

2. Added safety checks to avoid potential nil dereference in the node's code. The potential nil dereference issues were found by Uber's nilaway tool (link).
   nilaway's original reports are attached. Note, I did not fix potential errors in test code.

3. Removed the pairing query cache.

---

nilaway_reports.zip

Author Checklist

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I have...

• read the contribution guide
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• confirmed ! in the type prefix if API or client breaking change
• targeted the main branch
• provided a link to the relevant issue or specification
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• included the necessary unit and integration tests
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• reviewed state machine logic, API design and naming, documentation is accurate, tests and test coverage

[github-actions]

Test Results

2 204 tests   - 1   2 204 ✅  - 1   24m 22s ⏱️ - 1m 0s
  145 suites ±0       0 💤 ±0 
    7 files   ±0       0 ❌ ±0 

Results for commit 9218823. ± Comparison against base commit 6278d1a.

This pull request removes 1 test.

github.com/lavanet/lava/v3/x/pairing/keeper ‑ TestPairingQueryCache

♻️ This comment has been updated with latest results.