Harmonize ConfigurationProperties bean name

When `@EnableConfigurationProperties` is defined, Spring Boot
automatically registers a bean in the context for each class specified
on the annotation. Previously, the name of the bean only included the
prefix which leads to conflict if two different classes use the same
prefix.

This commit changes the bean name structure to be <prefix>-<fqn> where
prefix is the prefix used on the annotation and <fqn> the fully qualified
name of the target class.

Closes gh-4395

spring-boot-actuator-docs/src/main/asciidoc/configprops.adoc

@@ -3,8 +3,8 @@ This endpoint is a report on the Spring Boot `@ConfigurationProperties` beans. B
 this annotation are bound to the `Environment` on startup, so they reflect the
 externalised configuration of the application. Beans are listed by name. A bean that is
 added using `@EnableConfigurationProperties` will have a conventional name:
-`<prefix>.CONFIGURATION_PROPERTIES`, where `<prefix>` is the environment key prefix
-specified in the  `@ConfigurationProperties` annotation.
+`<prefix>-<fqn>`, where `<prefix>` is the environment key prefix specified in the
+`@ConfigurationProperties` annotation and <fqn> the fully qualified name of the bean.
 
 Example curl request:
 include::{generated}/configprops/curl-request.adoc[]