Publish tests for RequestAdapter

[enqueue]

It would be great if kiota-java provided some tests for implementors of RequestAdapter. It does not have to be a full-blown TCK, but perhaps a simple collection of test cases which providers could run to check for compatibility.

For example, I recently found out, that VertXAdapter treated "XXX" error code mappings differently from OkHttpRequestAdapter (see issue kiota-community/kiota-java-extra#373). I did not find anything specific about the behavior in the documentation about error handling. They only mention "ranges", with either 4 or 5 as first digits.

CC @andreaTP

[andreaTP]

I believe that having a consistent documentation about the expectation of the error mappings would be a first step in the right direction.
cc, @baywet