Implement SHA224 (#11)

* start of sha224 implements, tho quite simple

* Update pom.xml

just to make it compile main for testing, simplifies the process

src/main/java/de/caydenno1/xacrypto/hash/sha224/Helpers.java

@@ -0,0 +1,29 @@
+package de.caydenno1.xacrypto.hash.sha224;
+
+import static de.caydenno1.xacrypto.hash.ROT.ROTR;
+
+public class Helpers {
+    public static int ch(int x, int y, int z) {
+        return (x & y) ^ (~x & z);
+    }
+
+    public static int maj(int x, int y, int z) {
+        return (x & y) ^ (x & z) ^ (y & z);
+    }
+
+    public static int bigSigma0(int x) {
+        return ROTR(x, 2) ^ ROTR(x, 13) ^ ROTR(x, 22);
+    }
+
+    public static int bigSigma1(int x) {
+        return ROTR(x, 6) ^ ROTR(x, 11) ^ ROTR(x, 25);
+    }
+
+    public static int smallSigma0(int x) {
+        return ROTR(x, 7) ^ ROTR(x, 18) ^ (x >>> 3);
+    }
+
+    public static int smallSigma1(int x) {
+        return ROTR(x, 17) ^ ROTR(x, 19) ^ (x >>> 10);
+    }
+}