fix: nilaway fixes

[oren-lava]

Description

Closes: #XXXX

In this PR I 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.

nilaway_reports.zip

Author Checklist

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I have...

• read the contribution guide
• included the correct type prefix in the PR title, you can find examples of the prefixes below:
• confirmed ! in the type prefix if API or client breaking change
• targeted the main branch
• provided a link to the relevant issue or specification
• reviewed "Files changed" and left comments if necessary
• included the necessary unit and integration tests
• updated the relevant documentation or specification, including comments for documenting Go code
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• confirmed the correct type prefix in the PR title
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• reviewed state machine logic, API design and naming, documentation is accurate, tests and test coverage

[github-actions]

Test Results

2 184 tests  ±0   2 184 ✅ ±0   24m 10s ⏱️ -2s
  145 suites ±0       0 💤 ±0 
    7 files   ±0       0 ❌ ±0 

Results for commit 3f06d24. ± Comparison against base commit 200972c.