See gh-8768

Closes gh-8892

This commit improves `SpringApplicationAdminMXBeanRegistrar` so that it
work with traditional Servlet-based app but also with Spring WebFlux.

Closes gh-8533

Closes gh-8232

Closes gh-8885

Closes gh-6911

This commit makes sure to honour the `spring.aop.proxy-target-class`
property if set by the user. Previously, the
`PersistenceExceptionTranslationPostProcessor` was always configured to
use cglib, regardless of the value of that property.

Closes gh-8887

Closes gh-8497

This commit separates the JPA-specific bits of the batch
auto-configuration so that it is possible to reuse most of the logic if
JPA isn't available at all.

Closes gh-8877

Fixes gh-8883

See gh-8884

This commit makes sure to honour the `spring.aop.proxy-target-class`
property if set by the user. Previously, the
`MethodValidationPostProcessor` was always configured to use cglib,
regardless of the value of that property.

Closes gh-8869

* pr/8650:
  Polish "Add the ability to disable the trace filter"
  Add the ability to disable the trace filter

Closes gh-8650

See gh-8650

* pr/8813:
  Polish "Fix http status code with unknown log level"
  Fix http status code with unknown log level

Closes gh-8813

This commit changes the http status code to 400 when an unknown log level
is specified.

Closes gh-8798
See gh-8813

* pr/8879:
  Polish