Rename "Label" to a more fitting name for types, maybe "DimType"?

[benikm91]

[benikm91]

Note: Currently Label summon is just used in rearrange and printing shapes. Maybe it is worth considering to drop the Label typeclass all together. Not sure if we can still implement rearrange. shape printing would be possible but would print Generic shape names (compile time name; not runtime names) It would make implementing generic functions more straightforward...