MySQL cluster CR does not support append podSpec env

[xiaozhuang-a]

hello When I wanted to add an env for mysql cluster container mysql, I found that mysqlcluster_controller pod syncer does not support append custom env，code 。This resulted in me having to rebuild the image

As for why env needs to be added, as I am using the Percona server MySQL 5.7 image and need to use Jemalloc, I need to add an env LD_PRELOAD = /usr/lib64/libjemalloc.so.1。