### _Why are the changes needed?_
Currently, Flink engine would pull all result rows into memory before returning it to the client. This would be problematic for large result sets and infinite result sets.
This is a sub-task of KPIP-2 https://github.com/apache/incubator-kyuubi/issues/1322.
### _How was this patch tested?_
- [x] Add some test cases that check the changes thoroughly including negative and positive cases if possible
- [ ] Add screenshots for manual tests if appropriate
- [x] [Run test](https://kyuubi.apache.org/docs/latest/develop_tools/testing.html#running-tests) locally before make a pull request
Closes#1938 from link3280/feature/FLINK-1883.
Closes#1883
80020cee [Paul Lin] Update externals/kyuubi-flink-sql-engine/src/test/scala/org/apache/kyuubi/engine/flink/operation/FlinkOperationSuite.scala
1b958221 [Paul Lin] [KYUUBI #1883] Avoid allocating too much buffer space
5be7535c [Paul Lin] [KYUUBI #1883] Support max result rows for Flink queries
Authored-by: Paul Lin <paullin3280@gmail.com>
Signed-off-by: Kent Yao <yao@apache.org>
e54d431024