Merge #17450: util: Add missing headers to util/fees.cpp

b131524 util: Add missing headers to util/fees.cpp (Hennadii Stepanov)

Pull request description:

ACKs for top commit:
  laanwj:
    code review ACK b131524
  MarcoFalke:
    ACK b131524
  jnewbery:
    ACK b131524

Tree-SHA512: a1ad36bff12219912c6aaacd7d9dcbeccf0fa3373280fa6e804d7a4d267b485433d6e1c01134cfa6732d2fb30ec1ab4629dff6e4bea2fe4c1976180064a3c6ca

Author: MarcoFalke

src/util/fees.cpp

@@ -3,8 +3,11 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
+#include <util/fees.h>
+
 #include <policy/fees.h>
 
+#include <map>
 #include <string>
 
 std::string StringForFeeReason(FeeReason reason) {