Relevant commits on the old cleanup PR:
36933c7f5c7778e2d7fbfea5361c11fb41070467
21e43de0f300ee47b7e597098908601bf591950b
3c678bb1cedfd7b865ac2e7aaf014de4bfb3eb3d
In this repo, `boost::interprocess` was being used soley to make `uint32_t` operations atomic. So I replaced each instance of
`boost::interprocess::ipcdetail::atomic(...)32` with `std::atomic` methods. I replaced member declarations as applicable. For example,
when I needed to change a `volatile uint32_t` into a `std::atomic<uint32_t>`. Sometimes, a member was being used a boolean flag, so
I replaced it with `std::atomic<bool>`.
You may notice that I didn't touch `levin_client_async.h`. That is because this file is entirely unused and will be deleted in PR monero-project#8211.
Additional changes from review:
* Make some local variables const
* Change postfix operators to prefix operators where value was not need
