Since SPR-16946, Spring Framework revisited the DEBUG logging output
developers get while working on Spring MVC and Spring WebFlux
applications.

This commit aligns to those changes where DEBUG output was produced
in Spring Boot (especially in `DefaultErrorWebExceptionHandler`).

This also enables DEBUG logging on the related packages when running an
application with Spring Boot Developer Tools, providing a better
development experience.

This is also adding the new `spring.insights.web.log-request-details`
configuration property, which logs additional information about the
incoming requests at the DEBUG and TRACE levels. Since that information
can be sensitive (e.g. credentials, tokens, etc.), this property is not
enabled by default nor activated by the Developer Tools.

Closes: gh-13511