Remove unused includes from blockfilter.h

This removes unused includes, primitives/block found manually, and the
others by iwyu:

blockfilter.h should remove these lines:
- #include <serialize.h>  // lines 16-16
- #include <undo.h>  // lines 18-18

src/blockfilter.cpp

@@ -8,9 +8,11 @@
 #include <blockfilter.h>
 #include <crypto/siphash.h>
 #include <hash.h>
+#include <primitives/block.h>
 #include <primitives/transaction.h>
 #include <script/script.h>
 #include <streams.h>
+#include <undo.h>
 #include <util/golombrice.h>
 #include <util/string.h>