module: make a mod-rrl module from query_processing rrl code

Knot.files

doc/configuration.rst

doc/man/knot.conf.5in

doc/modules.rst

doc/reference.rst

src/Makefile.am

src/knot/conf/base.c

src/knot/conf/base.h

src/knot/conf/migration.c

src/knot/conf/migration.h

src/knot/conf/scheme.c

src/knot/conf/tools.c

src/knot/conf/tools.h

src/knot/modules/rrl/functions.c

src/knot/modules/rrl/functions.h

src/knot/modules/rrl/rrl.c

src/knot/modules/rrl/rrl.h

src/knot/nameserver/process_query.c

src/knot/nameserver/process_query.h

src/knot/nameserver/query_module.c