fix: equals and hashcode of several classes

Signed-off-by: christian.lutnik <[email protected]>

Author: chrfwow

src/test/java/dev/openfeature/sdk/MutableStructureTest.java

@@ -1,12 +1,12 @@
 package dev.openfeature.sdk;
 
+import static org.junit.jupiter.api.Assertions.*;
+
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Set;
 import org.junit.jupiter.api.Test;
 
-import static org.junit.jupiter.api.Assertions.*;
-
 class MutableStructureTest {
 
     @Test