[SPARSE] Add support for sparse gemv

[Rbiessy]

Description

Based on the changes from #374. The new changes are visible in the last commit.

Add support for sparse gemv using MKLCPU backend and add a test for it.

Checklist

All Submissions

• Do all unit tests pass locally? Attach a log.
• Have you formatted the code using clang-format?

New features

• Have you provided motivation for adding a new feature?
• Have you added relevant tests?

[Rbiessy]

Tests running locally using the 2023.2.0 oneapi package: tests_cpu.txt
Complex types are not supported in this version.

[Rbiessy]

Tests log using a recent nightly build of oneMKL: tests_cpu_nightly.txt
Complex are supported and passing now.

[Rbiessy]

Closing as it was merged with #374