Unicode logs/attributes support

[tobervenec]

Hi!
In most cases simple string_view or const char * is sufficient for needs of our project. But I wonder if there are some plans to extend logs/attributes with unicode support (Neither Logger functions nor AttributeValue seems to support wchar_t)?

Is your feature request related to a problem?
We are using logs/metrics (+traces in the future) quite extensively and recently a question was risen whether we can have at least unicode attributes (for example somebody wants to extend his log message with an attribute that represents some company name, which cannot be represented by ascii characters (chinese for example)).

Describe the solution you'd like
Would be nice to have a possibility to log messages and/or add attributes that can represent wider range of characters

Describe alternatives you've considered
One of alternatives I was thinking about is to have a possibility to send an array of bytes and corresponding encoding so that consumer knows how to interpret those bytes.

Additional context
Add any other context about the feature request here.