`renameToCamelCase` works is not as expected

[zaleslaw]

          it did from ID       ITEM  PRICE ORDER_DATE ->  iD       iTEM  pRICE  oRDERDATE"

Originally posted by @zaleslaw in #986 (comment)

It handles mostly the typical use-case, when we are reading from CSV file, created somewhere in Python, but when we are reading from the databases, it mostly using the capital letters, which we need to lowercase