add support to collect vectorudt with subarrays to fix #1200
add support to collect vectorudt with subarrays to fix #1200

rstudio/sparklyr,rstudio/sparklyr,rstudio/sparklyr,kevinykuo/sparklyr,kevinykuo/sparklyr,kevinykuo/sparklyr,kevinykuo/sparklyr,rstudio/sparklyr