We previously grouped all the license and notice files for httpcore, httpcore-nio, httpclient and httpasyncclient under the same license and notice file. There were though subtle differences between those which we didn't keep track of. For instance the httpcore license file has slightly changed since 4.4 which we have missed to track.
This commit goes back to having one license and notice file for each jar, to be completely sure that each dependency is associated with exactly the right licene and notice file.
Closes#25567