Add Ollama multimodality support

- Requires LLaVa or Bakllava models.
  - Extend the Ollama chat client to support the Spring AI Medi type inputs.
  - Add OllamaChatClientMultimodalIT.java
  - Add Multimodal section in Ollama's docs.

 Resolves #421

spring-ai-spring-boot-testcontainers/src/test/java/org/springframework/ai/testcontainers/service/connection/ollama/OllamaContainerConnectionDetailsFactoryTest.java

@@ -53,7 +53,7 @@ class OllamaContainerConnectionDetailsFactoryTest {
 
 	@Container
 	@ServiceConnection
-	static OllamaContainer ollama = new OllamaContainer("ollama/ollama:0.1.23");
+	static OllamaContainer ollama = new OllamaContainer("ollama/ollama:0.1.29");
 
 	@Autowired
 	private OllamaEmbeddingClient embeddingClient;