DRTVWR-493: Introduce test catch_what(), catch_llerrs() functions.

indra/llcommon/tests/lleventcoro_test.cpp

indra/llcommon/tests/lleventdispatcher_test.cpp

indra/llcommon/tests/lleventfilter_test.cpp

indra/llcommon/tests/llinstancetracker_test.cpp

indra/llcommon/tests/lllazy_test.cpp

indra/llcommon/tests/llleap_test.cpp

indra/llcommon/tests/llprocess_test.cpp

indra/llcommon/tests/wrapllerrs.h

indra/llmessage/tests/llareslistener_test.cpp

indra/newview/tests/llxmlrpclistener_test.cpp

indra/test/catch_and_store_what_in.h

indra/test/llevents_tut.cpp

indra/test/test.cpp