Closes gh-8899

Closes gh-7999

Closes gh-10709

* pr/10700:
  Polish

Closes gh-10700

See gh-10671

Following some changes in the latest snapshot this includes:
- Some updates to oauth2 client auto-config
- Security auto-config no longer relies on GlobalAuthenticationConfigurerAdapter
- Remove reactive security starter

Closes gh-10704

Closes gh-10671

Regardless of whether the web endpoints have been enabled or not,
all endpoints for which beans are created need to be exposed in a
CF environment under /cloudfoundryapplication.

Closes gh-10673

Closes gh-10684

This commit introduces a new mainClassName property on the springBoot
DSL provided by the Gradle plugin. It can be used to explicitly
configure the mainClassName of the default bootRun, bootJar, and
bootWar tasks in a single place. Previously, the only mechanism
provided to do so was the mainClassName property that's only available
when the application plugin has been applied.

Closes gh-10623

Previously, BootRun used the main property to configure the name of
the main class to run while BootJar and BootWar used the mainClass
property. Both were different to the application plugin which provides
a mainClassName project property.

This commit updates BootRun, BootJar, and BootWar to change the name
of the property used to configure the name of the main class to be
mainClassName. This makes the three Boot-specific tasks consistent
with each other, and also aligns them with Gradle's own application
plugin.

Closes gh-10622

Closes gh-10691

Closes gh-10687

Closes gh-10526

See gh-10679

Closes gh-10678

Closes gh-10677

Closes gh-10676

Closes gh-10675

Closes gh-10674

* pr/10670:
  Polish HttpHeaderInterceptor

Closes gh-10670

Closes gh-10477

Previously, we relied on Mockito's internals to bypass any Spring AOP
proxy during verification of a spy. Thanks to a new API in Mockito,
we can replace the use of Mockito's internals with a
VerificationStartedListener. This listener changes Mockito's view of
the mock to be the ultimate target of the AOP proxy, i.e. to be the
actual Mockito-created spy, allowing Mockito's verification of the
spy to proceed successfully.

This above-described change will mean that we require a very
up-to-date version of Mockito so the tests that verify our
compatibility with 2.5 have been removed as we will no longer support
it when using @MockBean or @SpyBean.

Lastly, two tests have been updated to replace their usage of the
internal MockUtil class with the equivalent public API calls.

Closes gh-10352

Closes gh-10668

Closes gh-10666

Closes gh-10647

* pr/10657:
  Remove "Securing the H2 console" section

Closes gh-10657