fix: traverseNodes unexpected behaviour

[catShaark]

• If there's no update in the latest version of the tree, we set the root node's value to be the previous root node's key instead of its marshalled bytes. When we call traverseNodes, we iterate through every nodes (including root nodes) and unmarshal the marshalled node's value via MakeNode. MakeNode is made only for unmarshaling a marshalled node's value, so if a marshalled node's value is actually a node's key like described above, it'll handle incorrectly.
• Suggest that in traverseNodes we check if the marshalled node's value is indeed a root node's key so that we can ignore it

[cool-develope]

@catShaark , thanks for catching it, it seems like we need to refactor the traverseNode function using prefixIterate
FYI, it is a test utility function (not critical part).

[catShaark]

should I close this now

[cool-develope]

should I close this now

or you can modify it

[catShaark]

ohh, I'll modify this

[catShaark]

adding more cases to the test

[tac0turtle]

@catShaark can we get a changelog here then we can merge

[catShaark]

Yess

[catShaark]

@tac0turtle, changelog added