Avoid duplicate descriptions in calendars

[philip-cline]

Checklist

• Appropriate branch selected (all PRs must first be merged to dev before they can be merged to master)
• Any modified or new methods or classes have helpful JavaDoc and code is thoroughly commented
• The description lists all applicable issues this PR seeks to resolve
• The description lists any configuration setting(s) that differ from the default settings
• All tests and CI builds passing

Description

The default description for a calendar in GTFS-lib will be autopopulated with a concatenation of the days of service it operates on. However, if multiple calendars operate on the same set of days, this will create duplicate descriptions which can become an issue for the datatools-ui display. This PR conditionally overrides any duplicates with the service-id, which is at least more useful than displaying duplicates.

You can test this with datatools-server set up to use this gtfs-lib hash and the latest datatools-ui.

[br648]

Works for me. I think dev needs to be merged into this PR? I built and tested gtfs-lib locally (by merging dev into this PR!). The remaining days of the week descriptions now look out of place, but I guess this doesn't matter. Make's we wonder why we even need a description!

[miles-grant-ibigroup]

Working