In azure openai extension, need a way to override the base url

Fixes #149

Author: edeandrea

openai/azure-openai/runtime/src/main/java/io/quarkiverse/langchain4j/azure/openai/runtime/AzureOpenAiRecorder.java

@@ -90,8 +90,11 @@ public Object get() {
     }
 
     private String getBaseUrl(Langchain4jAzureOpenAiConfig runtimeConfig) {
-        return String.format("https://%s.openai.azure.com/openai/deployments/%s", runtimeConfig.resourceName(),
-                runtimeConfig.deploymentId());
+        var baseUrl = runtimeConfig.baseUrl();
+
+        return !baseUrl.trim().isEmpty() ? baseUrl
+                : String.format("https://%s.openai.azure.com/openai/deployments/%s", runtimeConfig.resourceName(),
+                        runtimeConfig.deploymentId());
     }
 
     public void cleanUp(ShutdownContext shutdown) {

openai/azure-openai/runtime/src/main/java/io/quarkiverse/langchain4j/azure/openai/runtime/config/Langchain4jAzureOpenAiConfig.java

@@ -22,6 +22,13 @@ public interface Langchain4jAzureOpenAiConfig {
      */
     String deploymentId();
 
+    /**
+     * The base url for the Azure OpenAI resource. Defaults to
+     * {@code https://${quarkus.langchain4j.azure-openai.resource-name}.openai.azure.com/openai/deployments/${quarkus.langchain4j.azure-openai.deployment-id}}.
+     */
+    @WithDefault("https://${quarkus.langchain4j.azure-openai.resource-name}.openai.azure.com/openai/deployments/${quarkus.langchain4j.azure-openai.deployment-id}")
+    String baseUrl();
+
     /**
      * The API version to use for this operation. This follows the YYYY-MM-DD format
      */