Extract all the "am I a server" functions from router.c

src/app/config/config.c

src/app/config/statefile.c

src/app/main/main.c

src/core/include.am

src/core/mainloop/connection.c

src/core/mainloop/mainloop.c

src/core/or/channelpadding.c

src/core/or/channeltls.c

src/core/or/circuitbuild.c

src/core/or/circuituse.c

src/core/or/command.c

src/core/or/connection_edge.c

src/core/or/connection_or.c

src/core/or/dos.c

src/core/or/policies.c

src/core/or/status.c

src/feature/control/control.c

src/feature/dircache/dircache.c

src/feature/dircache/dirserv.c

src/feature/dirclient/dirclient.c