Add methods for reading/writing longs and doubles to PacketSerializer

Author: ConnorLinfoot

src/main/java/net/hypixel/modapi/serializer/PacketSerializer.java

@@ -58,6 +58,24 @@ public PacketSerializer writeVarInt(int value) {
         return this;
     }
 
+    public long readLong() {
+        return this.buf.readLong();
+    }
+
+    public PacketSerializer writeLong(long value) {
+        this.buf.writeLong(value);
+        return this;
+    }
+
+    public double readDouble() {
+        return this.buf.readDouble();
+    }
+
+    public PacketSerializer writeDouble(double value) {
+        this.buf.writeDouble(value);
+        return this;
+    }
+
     public String readString() {
         return this.readString(MAX_STRING_LENGTH);
     }