995x - Signposting fixes

[qqmyers]

What this PR does / why we need it: This addresses several issues raised by the community in signposting - two related to the format of output that wasn't per the spec, one regarding the mimetype used for a link, and one to avoid a potential issue where auto-updates of the page were failing in 5.14. (For the last one, it appears that 6.0 offers a fix. The fixes here will assure if workingversion == null for signposting occurs, it will not result in an exception that stops processing. They also add a check to make sure the versionId is set in the DatasetPage.refresh method, which was the problem in v5.14 as described in #9954.)

Which issue(s) this PR closes:

• Closes Link headers for "license" are missing the <...> brackets #9952
• Closes Extraneous information in linkset JSON #9953
• Closes Dataset status change isn't visible after publish on auto refreshed dataset page (v5.14)  #9954
• Closes Linkset contains links that are rejected by the API  #9957

Special notes for your reviewer:

Suggestions on how to test this: For the first two, read the issue and assure that the output now matches, i.e. <> chars exist in the license line and calling the linkset api doesn't return a linkset object as a child of a "data" json object. For the third, verify the mimetype used for the link in the issue is application/ld_json and verify the curl command in the issue - changed to use the new mimetype - works. For the last - as of now, regression testing that publishing a dataset works with the page finally updating to the published version is all we can do in 6.x. This is because 6.0 has changes that fix the known test cases and we don't know if the problem still exists in 6.x (with the fixes, if the problem does occur, we'll get waning messages in the log rather than having the dataset page display/refresh fail). FWIW, I did verify that the fixes here worked/works at QDR prior to the 6.0 fix.

Does this PR introduce a user interface change? If mockups are available, please link/include them here:

Is there a release notes update needed for this change?: added.

Additional documentation:

[coveralls]

coverage: 20.035% (-0.003%) from 20.038% when pulling 3629cb6 on GlobalDataverseCommunityConsortium:GDCC/Signposting into 7e0738e on IQSS:develop.

[pdurbin]

For my reference, the original Signposting PR:

• #8981

I'm just asking a question in this review.

Related issues and PRs:

• #9941
• #9940

[pdurbin]

There's a failing test:

java.lang.NullPointerException: Cannot invoke "jakarta.json.JsonArray.getJsonObject(int)" because the return value of "jakarta.json.JsonObject.getJsonArray(String)" is null
at edu.harvard.iq.dataverse.api.SignpostingIT.testSignposting(SignpostingIT.java:96)

See https://jenkins.dataverse.org/job/IQSS-Dataverse-Develop-PR/job/PR-9955/6/testReport/edu.harvard.iq.dataverse.api/SignpostingIT/testSignposting/

[pdurbin]

I added some docs and tests in 9f0b810. @qqmyers if I added any inaccuracies, please correct them!

I also merged the latest from develop.

[pdurbin]

Looks good!