starpu: Try to split what can be public if the user wants to add its own insert_task functions from what needs to remain private

Otherwise, it triggers:
```
runtime/starpu/codelets/codelet_gemmex.c:176:13: warning: assignment discards ‘const’ qualifier from pointer target type [-Wdiscarded-qualifiers]
  176 |     cl_name = chameleon_codelet_name( cl_name, 3,
```

The _ex() version allows to provide a task name, which is useful when
using StarPU's profiling interface.

LISITO Alycia authored 8 months ago and Mathieu Faverge committed 6 months ago

zgetrf/cmake: add a test to detect if STARPU_NONE is correctly defined to be used with getrf algortihm or not

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