[BEAM-12434] Implement side_input for num_shards in iobase (#14916)
[BEAM-12434] Implement side_input for num_shards in iobase (#14916)

Co-authored-by: Udi Meiri <2791048df333003e09821bad86d0778a0a179efe@users.noreply.github.com>
Co-authored-by: Johan Sternby <80c28f0754617d7cfeae43a5992444f513553cfb@axis.com>
chamikaramj/beam,lukecwik/incubator-beam,apache/beam,lukecwik/incubator-beam,lukecwik/incubator-beam,lukecwik/incubator-beam,lukecwik/incubator-beam,robertwb/incubator-beam,apache/beam,robertwb/incubator-beam,chamikaramj/beam,lukecwik/incubator-beam,apache/beam,chamikaramj/beam,robertwb/incubator-beam,robertwb/incubator-beam,apache/beam,robertwb/incubator-beam,chamikaramj/beam,apache/beam,apache/beam,chamikaramj/beam,chamikaramj/beam,robertwb/incubator-beam,lukecwik/incubator-beam,chamikaramj/beam,robertwb/incubator-beam,chamikaramj/beam,apache/beam,robertwb/incubator-beam,lukecwik/incubator-beam,apache/beam,lukecwik/incubator-beam,apache/beam,apache/beam,lukecwik/incubator-beam,chamikaramj/beam,chamikaramj/beam,robertwb/incubator-beam,robertwb/incubator-beam,apache/beam