[mlir][nvgpu] NVGPU Tutorials (#87065)

I have a tutorial at EuroLLVM 2024 ([Zero to Hero: Programming Nvidia
Hopper Tensor Core with MLIR's NVGPU
Dialect](https://llvm.swoogo.com/2024eurollvm/sess

[mlir][nvgpu] NVGPU Tutorials (#87065)

I have a tutorial at EuroLLVM 2024 ([Zero to Hero: Programming Nvidia
Hopper Tensor Core with MLIR's NVGPU
Dialect](https://llvm.swoogo.com/2024eurollvm/session/2086997/zero-to-hero-programming-nvidia-hopper-tensor-core-with-mlir's-nvgpu-dialect)).
For that, I implemented tutorial codes in Python. The focus is the nvgpu
dialect and how to use its advanced features. I thought it might be
useful to upstream this.

The tutorial codes are as follows:
- **Ch0.py:** Hello World
- **Ch1.py:** 2D Saxpy
- **Ch2.py:** 2D Saxpy using TMA
- **Ch3.py:** GEMM 128x128x64 using Tensor Core and TMA
- **Ch4.py:** Multistage performant GEMM using Tensor Core and TMA
- **Ch5.py:** Warp Specialized GEMM using Tensor Core and TMA

I might implement one more chapter:

- **Ch6.py:** Warp Specialized Persistent ping-pong GEMM

This PR also introduces the nvdsl class, making IR building in the
tutorial easier.

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