schemas/public_.sql: taxonlabel: added index on taxonomicname to facilitate retrieving rows from tnrs_input_name

inputs/.TNRS/schema.sql: added taxon_name_is_safe()

inputs/.TNRS/schema.sql: added unsafe_taxon_names()

schemas/public_.sql: sync_*(): renamed to *_modify() to facilitate finding these functions when modifying the corresponding view (using the new naming convention for a view's on-modify function)

bugfix: inputs/.TNRS/schema.sql: MatchedTaxon_modify(): updated to include taxon_scrub derived fields

bugfix: schemas/util.sql: mk_drop_from_create(): need to match first rather than last CREATE

inputs/.TNRS/schema.sql: *_modify(): allow running without a view_query, as recreate_view() now supports this

schemas/util.sql: recreate_view(): support omitting the view_query if the view has already been modified (eg. for public.*_view, which allow changing the view as a separate step)

fix: schemas/public_.sql: sync_*(): use util.copy() instead of CREATE TABLE AS so that table and column comments are also copied. this avoids the need to separately add the same comments to the view and its materialized table.

bugfix: schemas/util.sql: recreate(): need to handle case where util.mk_drop_from_create() is NULL