Add toString() methods to java point classes

Useful for debugging.

server/src/com/genymobile/scrcpy/Point.java

@@ -30,4 +30,13 @@ public class Point {
         return screenHeight;
     }
 
+    @Override
+    public String toString() {
+        return "Point{" +
+                "x=" + x +
+                ", y=" + y +
+                ", screenWidth=" + screenWidth +
+                ", screenHeight=" + screenHeight +
+                '}';
+    }
 }

server/src/com/genymobile/scrcpy/RawPoint.java

@@ -17,4 +17,11 @@ public class RawPoint {
         return y;
     }
 
+    @Override
+    public String toString() {
+        return "RawPoint{" +
+                "x=" + x +
+                ", y=" + y +
+                '}';
+    }
 }