Add support for camel case column names in target for insert-from-sql

[hlcianfagna]

This allows insert-from-sql to be used in situations like the below:

CREATE TABLE tbl1("COL1" int);
INSERT INTO tbl1 SELECT 1;
CREATE TABLE tbl2("COL1" int);

cr8 insert-from-sql \
   --src-uri "postgresql://crate@localhost:5432/doc" \
   --query "SELECT * FROM tbl1" \
   --hosts localhost:4200 \
   --table doc.tbl2