Move the o2-sim device implementations into source files

This moves the implementation of the o2-sim primary server, worker and hit merger devices out of their headers.

- The three device headers defined all member functions and several non-inline free functions.
- Each header now declares its class; the definitions are in O2PrimaryServerDevice.cxx, O2SimDevice.cxx and O2HitMerger.cxx, compiled into their runners.
- querySimConfig moves from O2SimDevice to PrimaryServerState.cxx, so the hit merger no longer includes the worker and macro/o2sim.C.
- The helpers in SimPublishChannelHelper.h are now inline, and PrimStateToString is inline constexpr.
- The unused nested TMessageWrapper of the hit merger and CustomCleanup of the worker are removed.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Author: sawenzel

run/CMakeLists.txt

@@ -55,7 +55,7 @@ add_library(internal::allsim ALIAS allsim)
 
 o2_add_executable(device-runner
                   COMPONENT_NAME sim
-                  SOURCES O2SimDeviceRunner.cxx
+                  SOURCES O2SimDeviceRunner.cxx O2SimDevice.cxx PrimaryServerState.cxx
                   PUBLIC_LINK_LIBRARIES internal::allsim)
 
 o2_add_executable(serial
@@ -80,7 +80,7 @@ o2_add_executable(sim
 
 o2_add_executable(primary-server-device-runner
                   COMPONENT_NAME sim
-                  SOURCES O2PrimaryServerDeviceRunner.cxx
+                  SOURCES O2PrimaryServerDeviceRunner.cxx O2PrimaryServerDevice.cxx
                   PUBLIC_LINK_LIBRARIES internal::allsim
                   TARGETVARNAME simexe)
 if(ENABLE_UPGRADES)
@@ -105,7 +105,7 @@ endif()
 
 o2_add_executable(hit-merger-runner
                   COMPONENT_NAME sim
-                  SOURCES O2HitMergerRunner.cxx
+                  SOURCES O2HitMergerRunner.cxx O2HitMerger.cxx PrimaryServerState.cxx
                   PUBLIC_LINK_LIBRARIES internal::allsim)
 
 o2_add_executable(g4-determine-unknown-pdg-properties