Mixed Precision / Fix small issues in the conversion kernels for a better propagation of the information in distributed

See merge request !474

starpu: Add an shm insert task macro and change the data conversion tasks to local tasks to avoid issue with tag registrations

Fix coverity issues

See merge request !473

Issue #127: Fix the protection of half precision kernels with cuda

Closes #127

See merge request !470

bench plafrim: update guix and use new mkl oneapi 2023 package

See merge request !471

ci: add cmake export and pkg-config checks

See merge request !469

Many minor hotfix issued from the mixed precision branch

See merge request !468

context: Add a function to return the chameleon context in order to be able to use the public runtime API

Use blocked algorithm as the default one

See merge request !467