Rework support of AstraDB and Cassandra

[clun]

In the Datastax Astra DB saas solution, a new way to integrate with vector databases has been introduced: using an HTTP APi instead of the Cassandra Cluster. It is called the DataAPI and use the MongoDB principles with collections.

The pull request includes the following:

Update on previous implementations

• Previous implementations of embedding stores have been grouped in a single CassandraEmbeddingStore. It can be instantiated for Astra or OSS Cassandra based on 2 different constructor builders but everything else is the same.

• Previous implementations of chat memory stores have been grouped in a single CassandraChatMemoryStore. It can be instantiated for Astra or OSS Cassandra based on 2 different constructor builders but everything else is the same.

• Integration test for OSS Cassandra now using test containers (as Cassandra 5-alpha2 image is out)

• Usage

// Using with Astra (Cassandra AAS in the cloud)
CassandraEmbeddingStore.builderAstra()
  .token(token)
  .databaseId(dbId)
  .databaseRegion(TEST_REGION)
  .keyspace(KEYSPACE)
  .table(TEST_INDEX)
  .dimension(11)
  .metric(CassandraSimilarityMetric.COSINE)
  .build();

// Using OSS Cassandra
CassandraEmbeddingStore.builder()
  .contactPoints(Arrays.asList(contactPoint.getHostName()))
  .port(contactPoint.getPort())
  .localDataCenter(DATACENTER)
  .keyspace(KEYSPACE)
  .table(TEST_INDEX)
  .dimension(11)
  .metric(CassandraSimilarityMetric.COSINE)
  .build();

-Adding jdk11 in the pom

<maven.compiler.source>11</maven.compiler.source>
<maven.compiler.target>11</maven.compiler.target>

• introducing insertMany(), distributed to all bulk loading

• Extending the variables EmbeddingStoreIT

• Using MessageWindowChatMemory for the tests.

[langchain4j]

Hi @clun thanks a lot for your contribution! I will check this next week after the release.

[langchain4j]

@clun great job, thank you!