bench: add CAddrMan benchmarks

The added benchmarks exercise the public methods Add(), GetAddr(),
Select() and Good().

src/Makefile.bench.include

@@ -12,6 +12,7 @@ GENERATED_BENCH_FILES = $(RAW_BENCH_FILES:.raw=.raw.h)
 
 bench_bench_bitcoin_SOURCES = \
   $(RAW_BENCH_FILES) \
+  bench/addrman.cpp \
   bench/bench_bitcoin.cpp \
   bench/bench.cpp \
   bench/bench.h \