schemas/util.sql: added canon_case(str text, case_sensitive boolean)

schemas/util.sql: check_constraint_disable(): documented that we can't use ADD CONSTRAINT NOT VALID for this because it does not disable the constraint completely, but instead causes new rows to be validated against it. the ADD CONSTRAINT NOT VALID behavior does not work for the derived columns use case of this function.

schemas/public_.sql: *_view_modify(): added repopulate param, which is passed to rematerialize_view()

schemas/util.sql: rematerialize_view(): support updating just the table's schema, without populating it

schemas/util.sql: rematerialize_view(): don't need extra eval() around table_mod_sql because recreate() performs eval()

lib/sh/sync.sh: db_snapshot(): before backing up, trim bloated temp files (eg. from rolled back changes)

bugfix: inputs/.TNRS/schema.sql: taxon_match: use wrapper for util.remove_prefix() so CHECK constraints that use it don't get dropped when the util schema is reinstalled

schemas/public_.sql: *_view_modify(): use util.rematerialize_view(), which now supports table mods

schemas/util.sql: rematerialize_view(): added support for table mods to run after creating table

bugfix: schemas/util.sql: rematerialize_view(): don't populate unless recreate() can successfully recreate the dependent views, to avoid populating the entire table (which for some views can take hours) only to have the changes rolled back by a failing dependent view