Move build system to meson-python

[ndgrigorian]

This PR proposes moving from scikit-build to meson-python as the mkl_umath build system

meson-python is already used by NumPy and eliminates the need for CMake, while also allowing setup.py to be removed (with its logic moved into the meson.build script)

Following the approach in NumPy, vendored/process_src_template.py is vendored from NumPy to be called from the build script, automating the processing of conv_template.py

This PR also adds building and testing with standard clang

Build option also changes:
The former CMake build options are now exposed as meson options and passed via -Csetup-args:
OPTIMIZATION_REPORT becomes -Csetup-args=-Dopt_report=true
MKL_THREADING becomes -Csetup-args=-Dmkl_threading=<layer>

[antonwolfy]

No more comments from me. The only concern if we have to pass the benchmark job before the merge.

[vlad-perevezentsev]

No more comments from me. The only concern if we have to pass the benchmark job before the merge.

What about macOS support?
Should it be added as was done for mkl-service and mkl_fft fix releases?

[vchamarthi]

@vlad-perevezentsev Benchmark pipeline checks now unblocked, Please check,

[ndgrigorian]

No more comments from me. The only concern if we have to pass the benchmark job before the merge.

What about macOS support? Should it be added as was done for mkl-service and mkl_fft fix releases?

After discussion, conclusion was to add OSX support. We should also add CI for the projects that uses OSX for conda builds

[antonwolfy]

@vlad-perevezentsev Benchmark pipeline checks now unblocked, Please check,

@vchamarthi, what is the way to verbose the benchmark results?

[antonwolfy]

LGTM! Thank you @vlad-perevezentsev