Added unit-independent search

dbrepo-metadata-db/setup-schema.sql

.../java/at/tuwien/api/database/table/columns/ColumnDto.java

...t/tuwien/entities/database/table/columns/TableColumn.java

dbrepo-search-db/init/indices/column.json

dbrepo-search-service/Dockerfile

dbrepo-search-service/Pipfile

dbrepo-search-service/Pipfile.lock

dbrepo-search-service/app/opensearch_client.py

dbrepo-search-service/omlib/__init__.py

dbrepo-search-service/omlib/constants.py

dbrepo-search-service/omlib/dimension.py

dbrepo-search-service/omlib/exceptions/__init__.py

dbrepo-search-service/omlib/exceptions/dimensionexception.py

...earch-service/omlib/exceptions/unitconversionexception.py

...-search-service/omlib/exceptions/unitidentityexception.py

dbrepo-search-service/omlib/measure.py

dbrepo-search-service/omlib/omconstants.py

dbrepo-search-service/omlib/rdf/__init__.py

dbrepo-search-service/omlib/rdf/om-2.0.rdf

dbrepo-search-service/omlib/scale.py