Refactored ChunkingApp in testing to support both psql and mysql & Bug fixes

Changed ChunkingApp in test to TSV extractor:

- In input files to load, changed 'null' to '\N' for natural support in
both psql and mysql
- Updated UDF files in example/chunking/udf, while the application.conf
for example/chunking is not updated yet.
- now chunking runs in mysql test.

Bug fixes:

- In inference, do not use SELECT INTO syntax (not supported by MySQL).
Use CREATE TABLE AS syntax.