Various misc. changes

replaced lemon namespace with skos namespace in turtle for lexicons

removed prov namespace from turtle for lexicons

changed methods called for instrument_instances

added conditionality on gcis:TableNumber

added conditionality to lines of turtle for instruments

further adjusted aforementioned commit to turtle for tables

other_identifiers to turtle for datasets

other_identifiers to turtle for instruments

other_identifiers to turtle for platforms

other_identifiers to turtle for orgs

Revert "further adjusted aforementioned commit to turtle for tables"

This reverts commit 8da0cc45b6fffcf4a44200c48188053272a64ebe.