Handle DOI URLs and prefixed DOIs

[larsgw]

Fixes #2729

Description

Handle DOI queries with DOI input that still contains a full DOI URL or a DOI with a doi: prefix.

Caveats

• This change requires a documentation update
  • I have made corresponding changes to the documentation
• My code passes the tox check, I can receive warnings about tests, documentation or both

Testing

• https://scholia.toolforge.org/doi/doi:10.3390/MICROORGANISMS12071299 should redirect to Q135390431
• https://scholia.toolforge.org/doi/https://doi.org/10.3390/MICROORGANISMS12071299 should redirect to Q135390431

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, ...)