fix: Chapter 10 AVL tree insertNode and removeNode functions

[Jeffzholy]

CHANGES:

1. remove if condition this.compareFn(key, node.key) === Compare.BIGGER_THAN in insertNode function
2. align all if condition code blocks with assignment statement node = xxx instead of half return statement and half assignment statement
3. align rotation/balance logic in removeNode function with insertNode function, because they share the same rotation logic
4. copy the same code to the TS file