Add StringSeries.concatenate

[bryevdv]

Pre-req for hypergraph implementation.

The Python "counterpart" for this would be __add__ which does not exist on the JS side, so I have simply mirrored the cudf::strings::concatenate API from libcudf as a static StringSeries.concatenate. Open to suggestion for better naming since there is already, e.g. concat for other things.

[AjayThorve]

looks good, but I can see the naming being a bit confusing although there are enough unique factors as well.

concat is applied to a stringSeries, whereas concatenate is a standalone function that accepts multiple stringSeries as a list? I think that should be fine

[trxcllnt]

what about StringSeries.append() and StringSeries.prepend()? Or do we already have those?

edit: on second thought, concatenate seems appropriate since the input is an entire Table of String columns.

[bryevdv]

@trxcllnt right concatenate is nice because you can pass any number of string columns at once. But it would be trivial to define prepend and append as convenience helpers if we wanted to

 public prepend(other: StringSeries,
                opts: ConcatenateOptions = {}): Series<Utf8String> {
    return StringSeries.concatenate([other, this], opts)
}

I guess I am +0 on that.

@AjayThorve exactly right. I suppoe if we wanted to be more explicit then concatenate_string_columns but that name seems a bit redundant given the method only exists on StringSeries

[bryevdv]

@trxcllnt says "ship it" so I will merge when green

[bryevdv]

Uhh

[bryevdv]

looks like it did merge! 🤷