Updates Model.java to be up to date with current OllamaAPI

Also adds Jackson-JSR310 for java.time JSON Mapping

pom.xml

@@ -149,7 +149,12 @@
         <dependency>
             <groupId>com.fasterxml.jackson.core</groupId>
             <artifactId>jackson-databind</artifactId>
-            <version>2.15.3</version>
+            <version>2.17.1</version>
+        </dependency>
+        <dependency>
+            <groupId>com.fasterxml.jackson.datatype</groupId>
+            <artifactId>jackson-datatype-jsr310</artifactId>
+            <version>2.17.1</version>
         </dependency>
         <dependency>
             <groupId>ch.qos.logback</groupId>

src/main/java/io/github/amithkoujalgi/ollama4j/core/models/Model.java

@@ -1,5 +1,7 @@
 package io.github.amithkoujalgi.ollama4j.core.models;
 
+import java.time.LocalDateTime;
+
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.core.JsonProcessingException;
 import io.github.amithkoujalgi.ollama4j.core.utils.Utils;
@@ -11,7 +13,9 @@ public class Model {
   private String name;
   private String model;
   @JsonProperty("modified_at")
-  private String modifiedAt;
+  private LocalDateTime modifiedAt;
+  @JsonProperty("expires_at")
+  private LocalDateTime expiresAt;
   private String digest;
   private long size;
   @JsonProperty("details")

src/main/java/io/github/amithkoujalgi/ollama4j/core/utils/Utils.java

@@ -8,10 +8,18 @@ import java.net.URISyntaxException;
 import java.net.URL;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
 
 public class Utils {
+
+  private static ObjectMapper objectMapper;
+
   public static ObjectMapper getObjectMapper() {
-    return new ObjectMapper();
+    if(objectMapper == null) {
+      objectMapper = new ObjectMapper();
+      objectMapper.registerModule(new JavaTimeModule());
+    }
+    return objectMapper;
   }
 
   public static byte[] loadImageBytesFromUrl(String imageUrl)