Allow ApplicationContextAotGenerator to generated better class names

Update `ApplicationContextAotGenerator` so that it can generate class
names based on a `target` class and using the ID of the application
context. Prior to this commit, the generated class name was always
`__.BeanFactoryRegistrations`.

Closes gh-28565

spring-beans/src/main/java/org/springframework/beans/factory/aot/BeanFactoryInitializationCode.java

@@ -18,6 +18,7 @@ package org.springframework.beans.factory.aot;
 
 import org.springframework.aot.generate.MethodGenerator;
 import org.springframework.aot.generate.MethodReference;
+import org.springframework.lang.Nullable;
 
 /**
  * Interface that can be used to configure the code that will be generated to
@@ -34,6 +35,24 @@ public interface BeanFactoryInitializationCode {
 	 */
 	String BEAN_FACTORY_VARIABLE = "beanFactory";
 
+	/**
+	 * Return the target class for this bean factory or {@code null} if there is
+	 * no target.
+	 * @return the target
+	 */
+	@Nullable
+	default Class<?> getTarget() {
+		return null;
+	}
+
+	/**
+	 * Return the ID of the bean factory or and empty string if no ID is avaialble.
+	 * @return the bean factory ID
+	 */
+	default String getId() {
+		return "";
+	}
+
 	/**
 	 * Return a {@link MethodGenerator} that can be used to add more methods to
 	 * the Initializing code.

spring-beans/src/main/java/org/springframework/beans/factory/aot/BeanRegistrationsAotContribution.java

@@ -61,8 +61,9 @@ class BeanRegistrationsAotContribution
 	public void applyTo(GenerationContext generationContext,
 			BeanFactoryInitializationCode beanFactoryInitializationCode) {
 
-		ClassName className = generationContext.getClassNameGenerator()
-				.generateClassName("BeanFactory", "Registrations");
+		ClassName className = generationContext.getClassNameGenerator().generateClassName(
+				beanFactoryInitializationCode.getTarget(),
+				beanFactoryInitializationCode.getId() + "BeanFactoryRegistrations");
 		BeanRegistrationsCodeGenerator codeGenerator = new BeanRegistrationsCodeGenerator(
 				className);
 		GeneratedMethod registerMethod = codeGenerator.getMethodGenerator()