* Add dynamic welcome message to p2p handshake

* Add '/welcome-msg' to debug api

* Add missing license headers

* Rename to WelcomeMessageSynced to Get

* Add atomic.value instead of struct

* Simplify mocks, refactor tests

* Add request struct and length check

* Extract DebugService p2p interface

* Add check

* Remove MaxBytesReader

* Remove unused constant

* Remove out of scope test

* Set max request size

* Refactor test