Faster Jackson default settings

By default Jackson does not enable faster features to ensure 100% backwards compatibility. They should be safe and are already in use by many projects.

Note that `USE_FAST_DOUBLE_WRITER` has been ported to Java 20 and so has been left out. Maybe something for the avaje native json to consider if not already (use built-in instead of custom)?

jsonb-jackson/src/main/java/io/avaje/jsonb/jackson/JacksonAdapter.java

@@ -1,6 +1,7 @@
 package io.avaje.jsonb.jackson;
 
 import com.fasterxml.jackson.core.JsonFactory;
+import com.fasterxml.jackson.core.StreamReadFeature;
 import com.fasterxml.jackson.core.io.SegmentedStringWriter;
 import com.fasterxml.jackson.core.util.ByteArrayBuilder;
 import io.avaje.jsonb.JsonIoException;
@@ -101,7 +102,10 @@ public Builder failOnUnknown(boolean failOnUnknown) {
      */
     public JacksonAdapter build() {
       if (jsonFactory == null) {
-        jsonFactory = new JsonFactory();
+        jsonFactory = JsonFactory.builder()
+          .enable(StreamReadFeature.USE_FAST_DOUBLE_PARSER)
+          .enable(StreamReadFeature.USE_FAST_BIG_NUMBER_PARSER)
+          .build();
       }
       return new JacksonAdapter(serializeNulls, serializeEmpty, failOnUnknown, jsonFactory);
     }
@@ -118,7 +122,7 @@ public JacksonAdapter build() {
   public JacksonAdapter() {
     this(false, false, false, new JsonFactory());
   }
-  
+
 
   public JacksonAdapter(JsonFactory factory) {
     this(false, false, false, factory);