Closes #3219: Optimize old Parquet srting read code

[bmcdonald3]

After seeing more results gathered on different machines showing mixed results for the new Parquet string optimization, we have decided to make some changes and go back towards a simpler optimization that we are more confident in across the board optimizations, though, they may be more minor than the "best case" with the optimized version, but we shouldn't be seeing any cases get worse with this approach, which seems preferable.