Double-check compute ops refactoring

[ahuber21]

In #196 copilot refactored the distance computations.

It is suspicious that carefully crafted implementations for L2 computations with different types ({float, float}, {float, fp16}, {float, int8}, {int8, int8}, etc.) are now all treated in the same SIMD op.

The task is to

• carefully evaluate every single line that changed and deduce if the operation it has been replaced with is identical;
• disassemble the compiled functions before and after the change and check for equivalence;
• perform unit testing with the compute primitives before and after the change and confirm they're producing the same output;
• perform benchmarking with the compute primitives before and after the change and confirm they achieve the same throughput (single-threaded).