Expand tst_QLocale::systemLocaleDayAndMonthNames() to more platforms

At present, tst_QLocale::systemLocaleDayAndMonthNames() only has test-cases defined for Darwin and ICU. We should at least support it also for the Unix back-end, which uses CLDR data, and preferably also for MS, if it's data are at least consistent across versions. Since Android uses (IIRC) ICU behind its Java API, we can probably just enable the test for it (we might not have feature icu enabled on Android).

This should mostly just be a matter of adding data for the other platforms; they need not mirror the test-cases on ICU and Darwin, although matching them as best we can is good.