Move `sortingcomponents` out of `spikeinterface`

[alejoe91]

sortingcomponents and spikeinterface have different targets (developers VS users) and development pace (fast VS slow).

I suggest factoring out sortingcomponents into its own package.

[zm711]

This would probably be most valuable for us if users of the package freely comment on if they use sortingcomponents (or which components they use) or avoid it completely.