Join ignores empty string as suffix

[ghing]

Join operations (I haven't tested this on all join operations, mostly just noticed it on left joins) will add a default suffix (i.e. "_1") to the common column names even when you explicitly specify an empty string as one of the suffixes.

Example code:

const t1 = aq.table({ colA: ["a", "b", "c"], colB: [3, 4, 5] });
const t2 = aq.table({ colA: ["a", "b", "c"], colB: [6, 7, 8] });
const joined = t1.join_left(t2, "colA", undefined, { suffix: ["", "_new"] });

Expected result:

colA	colB	colB_new
a	3	6
b	4	7
c	5	8

Observed result:

colA	colB_1	colB_new
a	3	6
b	4	7
c	5	8