Add break for default cases

Visual Studio has an option to search all files in a solution, so I
did a search in there for "default:" looking for any missing break
statements.

I've left out default statements that return something, and that throw
something, even if via ThrowInvalidType. UNREACHABLE leads towards throw

R_THROW macro leads towards a return

src/core/hle/service/service.cpp

@@ -228,6 +228,7 @@ Result ServiceFrameworkBase::HandleSyncRequest(Kernel::KServerSession& session,
         }
 
         UNIMPLEMENTED_MSG("command_type={}", ctx.GetCommandType());
+        break;
     }
 
     // If emulation was shutdown, we are closing service threads, do not write the response back to