Add support for DOI to QuickStatements

[carlinmack]

Builds on top of #2337. Merge #2337 before this PR

Roadmap

#2337: Add support for multiple ArXiv IDs

This PR: Add support for other identifiers (DOI for now) and change name

#2342: Add new tool which allows users to query for most recent papers which will be sent to this tool for finding presence in Wikidata and creating Quickstatements (CC @Daniel-Mietchen)

PR I'd like to do if I can:

• Upgrading citations.js (haven't been able to figure out) and potentially contributing some stuff upstream
• Ability to select which entries to copy/send to quickstatements
• Add checking whether Wikidata entries can be enriched

Description

Please include a summary of the change, relevant motivation and context. If possible and applicable, include before and after screenshots and a URL where the changes can be seen.

Introduces DOI to QuickStatements (using the Crossref API) resulting in renaming the tool to Identifier to QuickStatements.

Note that this does not affect the current /doi/[doi] tool which creates QuickStatements using Citations.js and has different behaviour.

Caveats

Please list anything which has been left out of this PR or which should be considered before this PR is accepted
Check any of the following which apply:

• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update
  • I have made corresponding changes to the documentation
• This change requires new dependencies (please list)

If you make changes to the Python code

• My code passes the tox check, I can receive warnings about tests, documentation or both

Testing

Please describe the tests that you ran to verify your changes. Provide instructions, so we can reproduce. Please also list any relevant details for your test configuration.

• I tested using identifiers found in Wikidata and not
• I created a test in test_utils.py to test the changes I made to string_to_type

Checklist

• I have commented my code, particularly in hard-to-understand areas
• My changes generate no new warnings
• I have not used code from external sources without attribution
• I have considered accessibility in my implementation
• There are no remaining debug statements (print, console.log, ...)

[cthoyt]

@carlinmack maybe interesting for you, Tiago and I have written a data model and utilities for quickstatements in Python: https://github.com/cthoyt/quickstatements_client. This could help reduce error-prone code in scholia

[fnielsen]

In command-line applications the webapp may not be running

[carlinmack]

Closed in favour of #2453