Fix system language dependent unit test

Summary:
When running the konsole unit tests on a system where the
language setting is not English the test
`ProfileTest::testFallbackProfile` fails because
 it compares the translated value of the `Name` property
 with the string literal `"Default"`. To fix the test we can
 use `UntranslatedName' instead.

Test Plan:
 # Run the konsole unit tests on a system where the language is not English

Output of `ctest --verbose` before the fix:

```
8: FAIL!  : Konsole::ProfileTest::testFallbackProfile() Compared values are not the same
8:    Actual   (fallback->property<QString>(Profile::Name)): "Standard"
8:    Expected (QStringLiteral("Default"))                 : "Default"
8:    Loc: [/var/run/media/peter/MEDIA/Projects/kde/konsole/src/autotests/ProfileTest.cpp(237)]
```

After the fix all tests should pass.

Reviewers: #konsole, hindenburg

Reviewed By: #konsole, hindenburg

Subscribers: hindenburg, konsole-devel

Tags: #konsole

Differential Revision: https://phabricator.kde.org/D15923