[FEAT] Add Thin Lens formula for ray optics (#7170)

* [FEAT] Add Thin Lens formula for ray optics

* [CI] Re-run clang-format checks

* [CI] Re-run checks after rebase

* [STYLE] Apply clang-format to ThinLensTest

---------

Co-authored-by: Koushik Sai <nyamathabadkoushik@gmail.com>

src/test/java/com/thealgorithms/physics/ThinLensTest.java

@@ -0,0 +1,19 @@
+package com.thealgorithms.physics;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.Test;
+
+class ThinLensTest {
+
+    @Test
+    void testConvexLensRealImage() {
+        double v = ThinLens.imageDistance(10, 20);
+        assertEquals(20, v, 1e-6);
+    }
+
+    @Test
+    void testMagnification() {
+        assertEquals(2.0, ThinLens.magnification(20, 10), 1e-6);
+    }
+}