Add ImmutableBeanCache - some parts of the query result graph populated via ImmutableBeanCache

[rbygrave]

An example:

1. Define a FetchGroup - this controls what is in each cache entry.

    // Label with associated labelTexts

    FetchGroup<Label> fetchGroup = FetchGroup.of(Label.class)
      .select("version")
      .fetch("labelTexts", "locale, localeText")
      .build();

2. Define a ImmutableBeanCache - using a built in implementation

ImmutableBeanCache<Label> labelCache = ImmutableBeanCaches.builder(Label.class)
  .loading(database, fetchGroup)
  .maxSize(10_000)
  .maxIdleSeconds(300)
  .maxSecondsToLive(6_000)
  .build();

3. Use the cache in a query

    AttributeDescriptor one = database.find(AttributeDescriptor.class)
      .setId(heightDescriptor.id())
      .setUnmodifiable(true)
      .using(labelCache) //  <!-- HERE 
      .findOne();

The Label instance that are part of resulting graph are Unmodifiable and populated from the labelCache.

Another example

FetchGroup<Customer> customerGroup = FetchGroup.of(Customer.class)
  .select("name,version")
  .fetch("billingAddress", "line1,city")
  .fetch("shippingAddress", "line1,city")
  .build();

ImmutableBeanCache<Customer> customerCache = ImmutableBeanCaches.builder(Customer.class)
  .loading(database, customerGroup)
  .build();

 database.find(Order.class)
  .using(customerCache)
  ...
  .findList()