* Move and rename NetPeerUtils
* Rename NetPeerUtils to NetPeerAttributes; inject instance instead of using a global var
* Rename SpanAttributeSetter to AttributeSetter (might be used to set on AttributesBuilder in the future, who knows)
* Deprecate default BaseTracer constructor: library instrumentations are supposed to inject all dependencies, the javaagent should explicitly pass globals
* fix compilation failure
* Remove peer.service customization from library instrumentation
* testing-common refactoring: replace direct AgentTestRunner usage with spock spec
* Updated instrumentation docs
* Fix reactor-core library tests
ReactorCoreTest was getting a tracer from GlobalOpenTelemetry before LibraryTestTrait had a change to initialize the SDK