we should be able to "fast-path" build a VarBinView since we know that the strings in values are unique (doesn't need to be in this PR)
Basically we can construct a VarBinView over the values, and then clone the view once for each code.
This also gets easier if we have #1110
Basically we can construct a VarBinView over the values, and then clone the view once for each code.
This also gets easier if we have #1110