test_string: Make 'stripWhiteSpace' test more complex
test_string: Make 'stripWhiteSpace' test more complex

No string without leading/trailing spaces was used in the test.

Signed-off-by: Martin Flaska <33679b43c310134d88bc5b061a2d9cdf7d8231bf@legrand.us>

taglib/taglib,black78/taglib,taglib/taglib,black78/taglib,TsudaKageyu/taglib,TsudaKageyu/taglib,black78/taglib,taglib/taglib,TsudaKageyu/taglib