Process manager should not attempt to unlink the processes database file in case of OperationalError

[kozlovsky]

This PR fixes #7931 by handling all OperationalError exceptions before DatabaseError exceptions, and by suppressing possible PermissionError exceptions when trying to remove the database filw after the DatabaseError

[drew2a]

NIT: The TestError class could be defined inside the test_connect_database_error_raise_non_permission_error function since it's only used there. This will increase the readability of the entire test file.

Suggested change

	class TestError(Exception):
	pass
	@patch('sqlite3.connect', MagicMock(side_effect=sqlite3.DatabaseError('error text')))
	@patch('pathlib.Path.unlink', MagicMock(side_effect=TestError))
	def test_connect_database_error_raise_non_permission_error(process_manager):
	# All OperationalError exceptions except "unable to open database file" should be re-raised
	with pytest.raises(TestError):
	with process_manager.connect():
	pass # pragma: no cover
	@patch('sqlite3.connect', MagicMock(side_effect=sqlite3.DatabaseError('error text')))
	@patch('pathlib.Path.unlink', MagicMock(side_effect=TestError))
	def test_connect_database_error_raise_non_permission_error(process_manager):
	class TestError(Exception):
	pass
	# All OperationalError exceptions except "unable to open database file" should be re-raised
	with pytest.raises(TestError):
	with process_manager.connect():
	pass # pragma: no cover