[EPIC]: Atomics Improvements

### Is this a duplicate?

- [X] I confirmed there appear to be no [duplicate issues](https://github.com/NVIDIA/cccl/issues) for this request and that I agree to the [Code of Conduct](CODE_OF_CONDUCT.md)

### Area

libcu++

### Description

Atomics today are missing critical features. This is a general roadmap and improvement checklist.

### Tasks
- [x] https://github.com/NVIDIA/cccl/pull/1993
- [x] https://github.com/NVIDIA/cccl/issues/2048
- [x] https://github.com/NVIDIA/cccl/issues/2051
- [ ] https://github.com/NVIDIA/cccl/issues/2049
- [ ] https://github.com/NVIDIA/cccl/issues/2050
- [ ] https://github.com/NVIDIA/cccl/issues/1188
- [ ] https://github.com/NVIDIA/cccl/issues/2052
- [ ] https://github.com/NVIDIA/cccl/issues/1103