Trusted Book Providers

- [x] #5271 Add basic flow for book providers
- [ ] Project Gutenberg
- Titles in catalogue: [~65,000](https://en.wikipedia.org/wiki/Project_Gutenberg)
- Editions in Open Library: [873](http://openlibrary.org/query.json?type=/type/edition&publishers=Project%20Gutenberg&limit=5000)
- Records in IA: [59,105](https://archive.org/details/gutenberg)
- Works in Open Library: [535](https://openlibrary.org/search?q=publisher%3A%22Project+Gutenberg%22&mode=everything)
- [x] Display read button when provider ID present
- [x] Custom download options
- [ ] Add Gutenberg ID to all the `publisher:Project Gutenberg` books currently in Open Library
- [ ] Import missing records
- [ ] Set up automatic import pipeline
- [ ] LibriVox
- Titles in catalogue: [~15,000](https://librivox.org/2021/02/14/librivox-celebrates-15000-audiobooks/)
- Editions in Open Library: [598](http://openlibrary.org/query.json?type=/type/edition&publishers=LibriVox&limit=5000)
- Works in Open Library: [423](https://openlibrary.org/search?q=publisher%3ALibriVox&mode=everything)
- Records in IA: [16,057](https://archive.org/details/librivoxaudio)
- [x] Display read button when provider ID present
- [x] Custom download options
- [x] Add proper LibriVox numeric ID to all the `publisher:LibriVox` books currently in Open Library
- [ ] #8105
- [ ] Get/crawl a dump of all librivox IDs
- [ ] Bulk import all librivox IDs
- [ ] Set up automatic import pipeline
- [x] Standard Ebooks
- Titles in catalogue: [589](https://standardebooks.org/ebooks?page=50)
- Editions in Open Library: [10](http://openlibrary.org/query.json?type=/type/edition&publishers=Standard%20Ebooks&limit=5000)
- Works in Open Library: [11](https://openlibrary.org/search?q=publisher%3A%22Standard+Ebooks%22&mode=everything)
- [x] Display read button when provider ID present
- [x] Custom download options
- [x] #3982
- [x] Import all standard ebooks books
- [x] Blocked by #5993
- [x] #5994
- [x] #6070
- [ ] OpenStax
- Titles in catalogue: [42](https://openstax.org/about)
- Works in Open Library: [~50](https://openlibrary.org/search?q=openstax&mode=everything)
- [ ] Tidy up the records
- [x] #6152
- [x] Remove accidental `openstax_id` field
- [x] Add proper openstax ID to every record
- [x] #6071 Display read button when provider ID present
- [x] #6071 Custom download options
- [x] #5577 Import missing records
- [ ] Set up automatic import pipeline
- [ ] Wikisource
- Titles in catalogue: [~500,000](https://en.wikisource.org/wiki/Main_Page) in English alone!
- No real presence in OL yet
- [x] Create identifier field for Wikisource
- Big Question: wikisource IDs are language specific (eg note the `en` in https://en.wikisource.org/wiki/Goody_Two-Shoes_(1888) ) :grimacing: how should we deal with that?
- Big Answer: Apparently URLs like this work! https://wikisource.org/wiki/en:The_Annotated_Strange_Case_of_Dr_Jekyll_and_Mr_Hyde
- [ ] Display read button when provider ID present
- [ ] Custom download options
- [ ] Import missing records
- [ ] Set up automatic import pipeline

Usability Improvements:
- [x] Add option to open a work to a specific provided edition (eg https://openlibrary.org/works/OL413631W/Roughing_It_in_two_volumes._2_2?edition=gutenberg%3A8583 )
- [x] Add option to prefer a provider in search results (eg https://openlibrary.org/search?mode=everything&q=publisher%3Aproject+gutenberg&sort=random&providerPref=gutenberg )
- [x] #5991
- [x] #5992
- [x] #5803 Not working on lists! Replace old availability.js with server-side LoanStatus
- [x] #8548
- [ ] #8546
- [ ] #8547

Marketing/discovery:
- [x] #5837
- [ ] Add collection page (for each provider?)

Bugs:
- [x] #5793
- [x] #5806
- [x] #5802
- [ ] OpenStax slugs redirect to latest edition for older editions :( Need to make metadata request. See https://github.com/internetarchive/openlibrary/pull/6138#pullrequestreview-883750756
- [x] #6379