Apply IWYU on epoch.cpp for <algorithm> and numbers.hpp for <array> (#4044)

nano/lib/epoch.cpp

@@ -1,6 +1,8 @@
 #include <nano/lib/epoch.hpp>
 #include <nano/lib/utility.hpp>
 
+#include <algorithm>
+
 nano::link const & nano::epochs::link (nano::epoch epoch_a) const
 {
 	return epochs_m.at (epoch_a).link;

nano/lib/numbers.hpp

@@ -3,6 +3,8 @@
 #include <boost/functional/hash.hpp>
 #include <boost/multiprecision/cpp_int.hpp>
 
+#include <array>
+
 namespace nano
 {
 using uint128_t = boost::multiprecision::uint128_t;