gh-91289: Reformat the text output of unittest

[ziima]

Fixed at EuroPython 24 sprints.

Based on the discussions at #91289 and EuroPython 24 sprints, I reformatted the text output of unittests to a single line for each test.

Example output:

This is an error docstring. (test_docstring.Foo.test_error) ... ERROR
test_docstring.Foo.test_error_no_doc ... ERROR
This is OK docstring. (test_docstring.Foo.test_ok) ... ok
test_docstring.Foo.test_ok_no_doc ... ok

======================================================================
ERROR: This is an error docstring. (test_docstring.Foo.test_error)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/tmp/pokus_unittest/test_docstring.py", line 9, in test_error
    raise Exception('Gazpacho!')
Exception: Gazpacho!

======================================================================
ERROR: test_docstring.Foo.test_error_no_doc
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/tmp/pokus_unittest/test_docstring.py", line 26, in test_error_no_doc
    raise Exception('Gazpacho!')
Exception: Gazpacho!

----------------------------------------------------------------------
Ran 4 tests in 0.004s

FAILED (errors=2)

The line contains docstring if conditions are met and removes the duplicate name of test method. It produces longer lines, but I think this is acceptable

Closes #91289

• Issue: gh-91289

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