Regression: Conversion between Username/Email and "remote" accounts (Institution, ORCID, Google, and GitHub) no longer works

[pdurbin]

https://build.hmdc.harvard.edu:8443/job/phoenix.dataverse.org-apitest-develop/286/testReport/ indicates that conversion from "remote" to "builtin" accounts no longer works:

This was first observed as of b632e40 which is just a merge of a doc change so I suspect the previous merge of pull request #5244 caused the regression.

[pdurbin]

As of dac897c (latest in develop branch, not release) here are the specific failures the API test suite is showing (all with the error "User doesn't know password"):

• migrateBuiltinToShib

  dataverse/src/test/java/edu/harvard/iq/dataverse/api/AdminIT.java

  Line 300 in dac897c

  Response makeShibUser = UtilIT.migrateBuiltinToShib(data, superuserApiToken);

• migrateBuiltinToOAuth

  dataverse/src/test/java/edu/harvard/iq/dataverse/api/AdminIT.java

  Line 392 in dac897c

  Response makeOAuthUser = UtilIT.migrateBuiltinToOAuth(data, superuserApiToken);

• migrateBuiltinToShib

  dataverse/src/test/java/edu/harvard/iq/dataverse/api/UsersIT.java

  Line 79 in dac897c

  Response makeShibUser = UtilIT.migrateBuiltinToShib(data, superuserApiToken);

My fix for these is pull request #5306.