Add implementations for CUDA library functions which dynamically load the CUDA...

Add implementations for CUDA library functions which dynamically load the CUDA library DSO and forward the call to the actual function. Most of the code is auto-generated.

Libraries implemented: CUDA driver API, cuRAND, cuFFT, cuBLAS, and cuDNN. The CUDA runtime is not implemented because it's not clear whether it should just be linked statically.

Older versions of CUDA (starting with 8.0) and cuDNN (starting with 7.0) are handled with two approaches:
- if the API didn't change and only new functions were added, declare types that were introduced afterwards. It is acceptable to implement APIs that were only introduced later: if they are called despite not being declared (in older headers), they will not be able to dlsym the corresponding function and return an error.
- if the API changed, different contextual headers are included.

PiperOrigin-RevId: 235135165