### What changes were proposed in this pull request?
This PR allows non-ascii string as an exception message in Python 2 by explicitly en/decoding in case of `str` in Python 2.
### Why are the changes needed?
Previously PySpark will hang when the `UnicodeDecodeError` occurs and the real exception cannot be passed to the JVM side.
See the reproducer as below:
```python
def f():
raise Exception("中")
spark = SparkSession.builder.master('local').getOrCreate()
spark.sparkContext.parallelize([1]).map(lambda x: f()).count()
```
### Does this PR introduce any user-facing change?
User may not observe hanging for the similar cases.
### How was this patch tested?
Added a new test and manually checking.
This pr is based on #18324, credits should also go to dataknocker.
To make lint-python happy for python3, it also includes a followup fix for #25814Closes#25847 from advancedxy/python_exception_19926_and_21045.
Authored-by: Xianjin YE <advancedxy@gmail.com>
Signed-off-by: HyukjinKwon <gurwls223@apache.org>
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