cmd, core, eth, light, trie: add trie read caching layer

vendor/github.com/allegro/bigcache/utils.go

@@ -0,0 +1,16 @@
+package bigcache
+
+func max(a, b int) int {
+	if a > b {
+		return a
+	}
+	return b
+}
+
+func convertMBToBytes(value int) int {
+	return value * 1024 * 1024
+}
+
+func isPowerOfTwo(number int) bool {
+	return (number & (number - 1)) == 0
+}