Alexander Andreev

# Description Changes proposed in this pull request: - Enable multithreaded QR, SVD and GEMM computation in one of SVD branches Has significant perf. improvement variance dependent on system specs.

Change SVM._fit_proba implementation

7

### Description Accelerates SVM._fit_proba by using prefit estimator in `CalibratedClassifierCV` instead of cross-validation. Solves https://github.com/intel/scikit-learn-intelex/issues/621. - [x] I have reviewed my changes thoroughly before submitting this pull request. - [x]...