[move-only] Move CAddrInfo to test-only header file

Now that no bitcoind callers require knowledge of the CAddrInfo object, it can
be moved into the test-only header file.

Review hint: use git diff --color-moved=dimmed-zebra
--color-moved-ws=ignore-all-space

src/test/fuzz/deserialize.cpp

@@ -4,6 +4,7 @@
 
 #include <addrdb.h>
 #include <addrman.h>
+#include <addrman_impl.h>
 #include <blockencodings.h>
 #include <blockfilter.h>
 #include <chain.h>