DDEntryPoint use active span in continueOrElseRoot

[slivkamiro]

dd-java-agent integrates automatically with some java server implementations already, e.g. netty. And so when using something like tapir-netty-server-cats in combination with natchez and DataDog I see two spans one for netty requests and other created by natchez, but they are not connected.
Would it make sense to you to consider checking activeSpan in DDEntryPoint during continueOrElseRoot ?
I can add PR if that's ok.
Thanks!