bug#70653: [PATCH] Support source line location for Python ExceptionGroup

[". shynur" <one.last.kiss@outlook.com>]

(This patch is written for Inferior Python mode.)

The original behavior considered only the case of
single exception:

```
Traceback (most recent call last):
  File "<string>", line 17, in __PYTHON_EL_eval
  File "c:/Users/shynur/Desktop/Python/a.py", line 1, in <module>
    raise Exception
Exception
```

In the above example, one can click at the 3rd line to jump
to the corresponding source line.  This patch adds support
for the following case (i.e., the built-in ExceptionGroup):

```
+ Exception Group Traceback (most recent call last):
  |   File "<string>", line 17, in __PYTHON_EL_eval
  |   File "c:/Users/shynur/Desktop/Python/a.py", line 1, in <module>
  |     raise ExceptionGroup("", [Exception()])
  | ExceptionGroup:  (1 sub-exception)
  +-+---------------- 1 ----------------
    | Exception
    +------------------------------------
```

--
shynur