test failure on Big Endian platforms

Hello, do we need to adapt also here for Big Endian?

[----------] 4 tests from QDltArgument
[ RUN ] QDltArgument.constructor
[ OK ] QDltArgument.constructor (0 ms)
[ RUN ] QDltArgument.string_ascii
./qdlt/tests/test_qdltargument.cpp:24: Failure
Expected equality of these values:
arg.getTypeInfo()
Which is: -2
QDltArgument::DltTypeInfoStrg
Which is: 0

[ FAILED ] QDltArgument.string_ascii (0 ms)
[ RUN ] QDltArgument.string_utf8
./qdlt/tests/test_qdltargument.cpp:48: Failure
Expected equality of these values:
arg.getTypeInfo()
Which is: -2
QDltArgument::DltTypeInfoUtf8
Which is: 7

[ FAILED ] QDltArgument.string_utf8 (0 ms)
[ RUN ] QDltArgument.setValueString
[ OK ] QDltArgument.setValueString (0 ms)
[----------] 4 tests from QDltArgument (0 ms total)

[----------] Global test environment tear-down
[==========] 4 tests from 1 test suite ran. (0 ms total)
[ PASSED ] 2 tests.
[ FAILED ] 2 tests, listed below:
[ FAILED ] QDltArgument.string_ascii
[ FAILED ] QDltArgument.string_utf8

Start with qdlt/tests/test_qdltargument.cpp, especially the string_ascii and string_utf8 cases and their getTypeInfo() assertions. Trace QDltArgument from those tests to determine why the values differ on Big Endian platforms. Done means the affected tests pass on Big Endian platforms while retaining the expected type information.

Written by the indexing model from the issue text.