Incorporate https://github.com/grails/scaffolding-old into fields plugin

[jamesfredley]

Fields is the only current plugin still using org.grails:scaffolding-core:2.1.0 which comes from https://github.com/grails/scaffolding-old and is archived. It was last released in 2019.

https://github.com/grails/scaffolding does not use https://github.com/grails/scaffolding-old (org.grails:scaffolding-core), so the decision was made to put the code in fields.

The code and docs have been incorporated directly into fields so that the code can be maintained here.

11 failing tests are currently ignored in this PR: 384dd19

This PR adds 114 passing tests for the scaffolding-old code.

[codeconsole]

@jamesfredley did you bring over the git history? If not, we should hold off. It's no difficult to do. you just add it as another source

[codeconsole]

This should be a subproject. All that is needed is to add the folder of the entire repo and add it to settings.gradle. That way all history is preserved. Alternatively we can unarchive the original project and keep it separate.

[jamesfredley]

@codeconsole the current situation with org.grails:scaffolding-core:2.1.0 and org.grails.plugins:scaffolding:6.0.0-SNAPSHOT is confusing, since they are not related and org.grails.plugins:scaffolding does not use org.grails:scaffolding-core.

Since org.grails:scaffolding-core is only used in Fields, I think that moving the code into it directly is the best place for it to live and evolve with that Plugin. The code was quite stale since it was out of sight in that old jar for the last 5 years.

I'll bring the git history (64 commits) over.

[jamesfredley]

replaced by #364