[MOVEONLY] consensus: move amount.h into consensus

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

src/wallet/coinselection.cpp

@@ -4,6 +4,7 @@
 
 #include <wallet/coinselection.h>
 
+#include <consensus/amount.h>
 #include <policy/feerate.h>
 #include <util/check.h>
 #include <util/system.h>