Upgrading (non-bijective) prefix maps

[cthoyt]

Motivated by https://github.com/mapping-commons/sssom-py/pull/485. Demo:

from curies import Converter, upgrade_prefix_map
pm = {"a": "https://example.com/a/", "b": "https://example.com/a/"}
records = upgrade_prefix_map(pm)
converter = Converter(records)

>>> converter.expand("a:1")
'https://example.com/a/1'

>>> converter.expand("b:1")
'https://example.com/a/1'

>>> converter.compress("https://example.com/a/1")
'a:1'

This function is for people who are not in the position to make the sustainable fix, and want to automate the assignment of which is the preferred prefix. It uses a deterministic algorithm to choose from two or more CURIE prefixes that have the same URI prefix and generate an extended prefix map in which they have bene collapsed into a single record. More specitically, the algorithm is based on a case-sensitive lexical sort of the prefixes. The first in the sort order becomes the primary prefix and the others become synonyms in the resulting record.

---

• [x] Implement function to deterministically make an EPM from a non-bijective prefix map
• [x] Pick a better name for this function
• [x] Implement first unit test
• [x] Think through this harder and implement more unit tests
• [x] Improve the function's docs
  • [x] Add params/returns
  • [x] Add examples inside the function
• [x] Add tutorial that gives context to this function (e.g., why do people get in the situation where they have non-bijective prefix maps, what are the consequences of making an automated approach to solving data issues vs. actually solving the data issue upstream).

cc @joeflack4