SPR-12429 introduced various `BEFORE_*` modes in `@DirtiesContext`. To
support these new modes, `DirtiesContextTestExecutionListener` (DCTEL)
was updated to support both `BEFORE_*` and `AFTER_*` modes. However,
there is a problem with having DCTEL support `BEFORE_*` modes since it
is typically configured to execute after the
`DependencyInjectionTestExecutionListener` (DITEL), and this leads to
several undesired side effects:

 - The test's `ApplicationContext` is closed by DCTEL *after*
   dependencies have been injected into the test instance.

 - Injected dependencies may therefore attempt to interact with an
   `ApplicationContext` that is no longer _active_.

 - If a test has its `ApplicationContext` injected as a dependency,
   interaction with the context will likely fail since the context has
   been closed.

 - Any `TestExecutionListeners` registered after DCTEL will get a _new_
   `ApplicationContext` if they invoke `getApplicationContext()` on the
   `TestContext`.

This commit fixes these issues by introducing a new
`DirtiesContextBeforeModesTestExecutionListener` (DCBMTEL) that is
registered by default before DITEL. The previous support for `BEFORE_*`
modes has been moved from DCTEL to DCBMTEL. In addition, an
`AbstractDirtiesContextTestExecutionListener` has been extracted from
DCTEL in order to avoid code duplication.

Issue: SPR-13180