Problem: memiavl's root hash is not safe to retain in commit info

[yihuang]

Solution:

• clone the byte slices when nesserary

👮🏻👮🏻👮🏻 !!!! REFERENCE THE PROBLEM YOUR ARE SOLVING IN THE PR TITLE AND DESCRIBE YOUR SOLUTION HERE !!!! DO NOT FORGET !!!! 👮🏻👮🏻👮🏻

PR Checklist:

• Have you read the CONTRIBUTING.md?
• Does your PR follow the C4 patch requirements?
• Have you rebased your work on top of the latest master?
• Have you checked your code compiles? (make)
• Have you included tests for any non-trivial functionality?
• Have you checked your code passes the unit tests? (make test)
• Have you checked your code formatting is correct? (go fmt)
• Have you checked your basic code style is fine? (golangci-lint run)
• If you added any dependencies, have you checked they do not contain any known vulnerabilities? (go list -json -m all | nancy sleuth)
• If your changes affect the client infrastructure, have you run the integration test?
• If your changes affect public APIs, does your PR follow the C4 evolution of public contracts?
• If your code changes public APIs, have you incremented the crate version numbers and documented your changes in the CHANGELOG.md?
• If you are contributing for the first time, please read the agreement in CONTRIBUTING.md now and add a comment to this pull request stating that your PR is in accordance with the Developer's Certificate of Origin.

Thank you for your code, it's appreciated! :)

[codecov]

Codecov Report

Merging #1150 (0a756f0) into main (265459d) will increase coverage by 0.06%.
The diff coverage is 100.00%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1150      +/-   ##
==========================================
+ Coverage   46.37%   46.44%   +0.06%     
==========================================
  Files         105      105              
  Lines        7855     7859       +4     
==========================================
+ Hits         3643     3650       +7     
+ Misses       3837     3836       -1     
+ Partials      375      373       -2     

Files Changed	Coverage Δ
memiavl/node.go	73.43% <ø> (ø)
memiavl/mem_node.go	95.16% <100.00%> (+0.07%)	⬆️
memiavl/persisted_node.go	94.53% <100.00%> (+0.08%)	⬆️
memiavl/tree.go	78.39% <100.00%> (ø)

... and 1 file with indirect coverage changes