Adding missing getters to ResourceSchema (#2486)

Author: yasmewad

smithy-aws-cloudformation/src/main/java/software/amazon/smithy/aws/cloudformation/schema/model/ResourceSchema.java

@@ -199,6 +199,10 @@ public Map<String, Property> getProperties() {
         return properties;
     }
 
+    public Set<String> getRequired() {
+        return required;
+    }
+
     public Set<String> getReadOnlyProperties() {
         return readOnlyProperties;
     }
@@ -235,6 +239,10 @@ public Tagging getTagging() {
         return tagging;
     }
 
+    public Schema getAdditionalProperties() {
+        return additionalProperties;
+    }
+
     public static final class Builder implements SmithyBuilder<ResourceSchema> {
         private String typeName;
         private String description;