Fix tracking of input rows/bytes for JOIN stages

This is a little hacky, since we should really be tracking
just the inputs due to the TableScan operator for any given
stage. However, the current stats rollup system doesn't
support this.
name of WITH query needs to be normalized to be case-insensitive
Add array concat operator

Added array-to-array, element-to-array, and array-to-element concat (||) support