Revert "GRAILS-11011: Add support for Junit ClassRule&Rule in unit test mixins"

This reverts commit 8b6f66659555add0fa774fd43ee0f66e68b33c2c.
refactor BaseApiProvider
- cache getParameterTypes call in BaseApiProvider
- add setProperties/getProperties methods to excluded methods
use GrailsMetaClassUtils.getExpandoMetaClass / GrailsMetaClassUtils.getMetaClass to get metaclass
- tests might load some instances with the ordinary MetaClassImpl instead of ExpandoMetaClass
catch exception in TagLibraryLookup initialization (occurs in unit tests when some beans are missing)
- exception started occuring after adding grailsApplicationAwareBeanPostProcessor bean to test context
Add Artefact annotation for Grails artefacts defined in test classes
- @Artefact("Controller") for controllers
- @Artefact("TagLib") for taglibs
Add ConvertersApi registration for Object[] and String[] metaclasses
GRAILS-11027 GRAILS-11011 Refactor Grails unit test mixins
- replace static @BeforeClass/@AfterClass methods with JUnit @ClassRule field
- replace @Before/@After methods with JUnit @Rule field
- implement simple "test runtime" plugin system
- move state from mixin classes to test plugins so that state can be shared and controlled
GRAILS-11027 Add ExpandoMetaClass.enableGlobally() to static initializer of test classes
remove "notYetImplemented()" from ControllerUnitTestMixinTests.testAllowedMethods
- test started passing after unit test mixin refactoring