Delete unit test class _04_PopulateTriageCodesFromPmidListTest

This class tested the population of TriageCorpus based on a list of pmids but now this step is performed while loading the Pdfs and hence this class is obsolete.
Revised some unit tests to populate triage corpora using pdfs instead of pmid lists
Revised the AA_CreateTriageDBTest unit test to populate triage corpus from pdf names instead of pmids list
Revised traget corpus name in some unit tests
Delete outdated Unit Test class