Closes #5373: where to allow bool_scalars

[ajpotts]

Closes #5373: where to allow bool_scalars

[1RyanK]

Minor performance issue on

In [7]: import time
   ...: import arkouda as ak
   ...: 
   ...: n = 20_000_000
   ...: x = ak.ones(n, dtype=ak.int64)
   ...: y = ak.zeros(n, dtype=ak.int64)
   ...: 
   ...: def time_where(cond):
   ...:     t0 = time.time()
   ...:     r = ak.where(cond, x, y)
   ...:     # force evaluation
   ...:     s = int(r.sum())
   ...:     t1 = time.time()
   ...:     return (t1 - t0), s
   ...: 
   ...: # Baseline: just sum x directly (should be fast-ish, no where mask)
   ...: t0 = time.time()
   ...: sx = int(x.sum())
   ...: t1 = time.time()
   ...: print("baseline x.sum() sec:", round(t1-t0, 3), "sum:", sx)
   ...: 
   ...: dt_true, s_true = time_where(True)
   ...: print("where(True, x, y) sec:", round(dt_true, 3), "sum:", s_true)
   ...: 
   ...: dt_false, s_false = time_where(False)
   ...: print("where(False, x, y) sec:", round(dt_false, 3), "sum:", s_false)
   ...: 
baseline x.sum() sec: 0.023 sum: 20000000
where(True, x, y) sec: 0.13 sum: 20000000
where(False, x, y) sec: 0.122 sum: 0

[jaketrookman]

Looks good