Dcicutils

=====
* Minor fix in structured_data to not try to resolve empty refs in norefs mode;
and added StructuredDataSet.unchecked_refs; not functionally substantive as
used (only) with smaht-submitr/submit-metadata-bundle --info --refs.
* Added nrows and nsheets to data_reader; convenience for smaht-submitr/submit-metadata-bundle --info.
* Added test_progress_bar module for progress_bar testing; would like to add more tests.
* Fixed up captured_output module to handle UTF-8 encoding to help unit testing progress_bar.
* Added hooks to progress_bar to help unit testing.
* Added a find_nth_from_end and set_nth to misc_utils to help progress_bar unit testing.
* Added format_size and format_duration misc_utils; refactor from smaht-submitr.
* Added format_datetime, parse_datetime to datetime_utils; refactor from smaht-submitr; and some tests.
* Added check_only flag to portal_utils.Portal.{post,patch}_metadata (came up in ad hoc troubleshooting).

=====
* Minor fix in structured_data related to smaht-submitr progress monitoring.
* Added progress_bar module (orginally lived in smaht-submitr).
* Added Portal.is_schema_type_file to portal_utils.
* Updated deployment_utils.py with support for GOOGLE_API_KEY in smaht-portal;
this is to get the version of the latest smaht-submitr metadata template;
and also similarly for SUBMITR_METADATA_TEMPLATE_SHEET_ID.

=====
* Support for ExtraFiles pseudo-type, to handle extra_files in smaht-submitr..
* Minor structured_data fix related to counting unresolved references;
not functionally consequential; only incorrect user feedback in smaht-submitr.
* Support in structured_data for norefs (completely ignore references).
* Minor fix in portal_object_utils.PortalObject._compare for lists.
* Minor structured_data changes for smaht-submitr validation/submission progress tracking.
* Minor structured_data code cleanup.
* Added submitr.progress_constants for sharing between smaht-submitr, snovault, smaht-portal;
not ideal living here but driving us nuts maintaining in separate locations;
and since we have this submitr sub-directory now, unified the common
ref_lookup_strategy function from smaht-submitr and smaht-portal.

=====
* Changes to troubleshooting utility script view-portal-object.
* Some reworking of ref lookup in structured_data.
* Support ref caching in structured_data.
* Added hook to turn off ref lookup by subtypes in case we need this later.
* Added hook do ref lookup at root path first; set to true by smaht-portal for accession IDs.
* Moved/adapted test_structured_data.py from smaht-portal to here.

=====
* Changes to structured_data support date/time types.
* Changes to structured_data support internal references in any order.
* New datetime_utils module and tests; first created for date/time support in structured_data.
* Added view-portal-object script for general troubleshooting.
* Change to data_reader to ignore sheet names enclosed in parenthesis.

=====

* Changes to itemize SMaHT submission ingestion create/update/diff situation (portal_object_utils).
* Changes to structured_data to handle property deletes (portal_object_utils).