To / from binary for map and set

The eqc tests collect output of the format

`{{size range}, {percent saving rang}}`

Where size is `{from, to}` eg from set it is the cardinality, so `{10, 20}` means a set with 10-20 elements.
For map size is the `term_to_binary` size `div 10`.

Percent saving of `{20, 30}` means that the `to_binary/1` output is 20-30% smaller than t2b for the same data.

Only when the data type is empty is t2b better (as far as I can tell.)