Update initialize call: include status backend URI

Update `"initialize"` API call to include status backend URI, to support API
changes from commit `7eeb5328e096f01d9e40dcf1adc233a56833d7b0` of the repo:

        https://github.com/gwg-placement-ga/vpr-v5-mod/
Replace all `iter.next` calls with `iter__next`

Replace all `iter.next` calls with `iter__next`, to support API changes from
commit `c03c29dcd0d9a7051d4664f81d68541414210e5e` of the repo:

    https://github.com/gwg-placement-ga/vpr-v5-mod/