[MOVEONLY] consensus: move amount.h into consensus

Move amount.h to consensus/amount.h.
Renames, adds missing and removes uneeded includes.

src/test/fuzz/integer.cpp

@@ -2,9 +2,9 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-#include <amount.h>
 #include <arith_uint256.h>
 #include <compressor.h>
+#include <consensus/amount.h>
 #include <consensus/merkle.h>
 #include <core_io.h>
 #include <crypto/common.h>