Possible Memory Leakage: `memmove()` and `memcpy()` are C Functions and are Not Promised in C++

[ATATC]

This is far from the first time we have been bothered by the lack of C++ standard library on Arduino. memmove() and memcpy() are both from the C library and do not always work with C++ classes (https://stackoverflow.com/a/37913835/20819839). Therefore, they should be replaced with safe alternatives in ArrayList to avoid possible memory leakages.