### _Why are the changes needed?_
to close#3820 .
To improve pyspark script support,
1. skip missing MagicNode implementation, since Jupyter and sparkmagic are not yet supported
2. add missing execute_reply_internal_error method
3. fix by calling clearOutputs before loop
4. ident lines and optimze unsed imports to conform python code style
5. Check Python major version , and exit on Python 2.x
6. fix name typo of `PythonResponse`
### _How was this patch tested?_
- [ ] 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#3819 from bowenliang123/imrove-pyspark.
Closes#3820
473b9952 [liangbowen] add return type to `connect_to_existed_gateway`
66927821 [liangbowen] remove unnecessary comments for magic code
21e1d7a2 [liangbowen] move pyspark path preparing to the top of exeuction_python
9751e094 [liangbowen] revert to use SparkSessionBuilder for session creation
c4f3ef55 [liangbowen] use `SparkSession._create_shell_session()` to create spark session
c2f65630 [liangbowen] delay importing kyuubi_util
5ed893cc [liangbowen] adding Exception to except, to prevent PEP 8: E203
029361a9 [liangbowen] ast module adaptation for >=3.8
00c75fda [liangbowen] remove legacy code for importing unicode
9f56a4f4 [liangbowen] add todo
1da708ed [liangbowen] fix typo for PythonResponse, and minor declaration improvement
910c62fb [liangbowen] remove MagicNode implementation since Jupyter and sparkmagic are not yet supported
5f15c257 [liangbowen] exit on python 2.x
86ff7d06 [liangbowen] ident lines to conform python code style
5634c5e0 [liangbowen] rename get_spark to get_spark_session, and optimize unused imports in kyuubi_util.py
9d3e1d0c [liangbowen] add missing MagicNode implementation
0ade1dbe [liangbowen] add missing execute_reply_internal_error method
aee205a5 [liangbowen] import cStringIO for fix package resolving problem
acdd4b16 [liangbowen] fix by calling clearOutputs before loop
Authored-by: liangbowen <liangbowen@gf.com.cn>
Signed-off-by: Cheng Pan <chengpan@apache.org>
3fae1845e7