Reasoner-validator

- Set default of compact_format to 'True' and title=None (suppress), in dumps() output.
- BMT upgraded to 1.0.8

- Added the ValidationReporter.dumps() method which directly returns the string created by ValidationReporter.dump() but without the need for an explicit file device

- added validation to explicitly detect presence of at least one concrete (non-abstract, non-mixin) category in categories list
- refactored the codes.yaml code both to fix validation code deficiencies, distinctly record validation context, and to simplified template messages
- finalized a first release of 'dump()', a significantly enhanced human-readable text report formatter for validation code associated messages

- added some code inadvertently not committed in v3.4.10.
- fixed various validation codes including swapping 'identifier' indexing for reduced redundancy
- enhanced dumping of human-readable messages for validation

- reasoner_validator.biolink.BiolinkValidator.validate_category() now only returns a non-None value if it is a 'concrete' category, and reports 'unknown' or 'missing' (None or empty string) category names as errors; deprecated categories are reported as warnings; but both 'mixin' and 'abstract' categories are accepted as valid categories silently ignored, but are not considered 'concrete', thus the method returns None. Bottom line is when at least one valid 'concrete' `category` is provided in the subject/object category input edges, or categories list for TRAPI query or knowledge graphs, and if all identifiers provided have a namespace recorded in the `id_prefix` slot list of at least one provided 'concrete' category, then the edge categories and ids will properly validate.

- Split the qualifier validation reporting into distinct codes for the qualifier_type_id ("**qualifier.type_id.unknown**") versus `qualifier_value` ("**qualifier.value.unresolved**")
- `ars_uuid_result_test_runner.py` made slightly more user friendly