This commit introduces support in the Spring TestContext Framework
(TCF) to query whether the test's ApplicationContext is available.
Specifically, this commit introduces the following two `default`
methods along with corresponding implementations in DefaultTestContext
and DefaultCacheAwareContextLoaderDelegate.
- `boolean hasApplicationContext()` in the TestContext API
- `boolean isContextLoaded(MergedContextConfiguration)` in the
CacheAwareContextLoaderDelegate API
Closes gh-22756
c3d0459a4e