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/wallet/test/util.cpp

@@ -9,6 +9,7 @@
 #include <key_io.h>
 #include <streams.h>
 #include <test/util/setup_common.h>
+#include <validationinterface.h>
 #include <wallet/context.h>
 #include <wallet/wallet.h>
 #include <wallet/walletdb.h>

src/wallet/test/wallet_tests.cpp

@@ -21,6 +21,7 @@
 #include <test/util/setup_common.h>
 #include <util/translation.h>
 #include <validation.h>
+#include <validationinterface.h>
 #include <wallet/coincontrol.h>
 #include <wallet/context.h>
 #include <wallet/receive.h>