Rethink `USE_ALIGNED_ACCESS` macro in kvrocks code

### Search before asking

- [X] I had searched in the [issues](https://github.com/apache/kvrocks/issues) and found no similar issues.

### Motivation

Redis uses `USE_ALIGNED_ACCESS` and check memory aligned in it's code:
1. For archs like ARM, memory access should be "aligned".
2. For arch like x86, it can use some code to do optimizations

This code leaves lots of ad-hoc optimizations in kvrocks. I think we need to check our compiler supports, does this really provides any optimizations

### Solution

1. Checks `USE_ALIGNED_ACCESS` in code with compiler versions
2. Remove them if no really optimizations

### Are you willing to submit a PR?

- [X] I'm willing to submit a PR!

No files, tests, or entry points are named. Search the codebase for USE_ALIGNED_ACCESS, then inspect the compiler-version checks and the related alignment or optimization paths. Done means determining whether each conditional provides a real supported optimization and removing or retaining the ad-hoc checks accordingly.

Written by the indexing model from the issue text.