Enable forking of phenotypes

[DSThayer]

1. Clicking "fork" leads to the create new phenotype, but with content populated (except things that would be specific to the new phenotype, like authors, publications). A new one is created only if they finish populating it and pressing save.
2. Some items are specific to the old phenotype (authors, publications) and are blank after forking.
3. Only published content can be forked. (Copying your own unpublished phenotype to create new content may be a useful, separate feature--to be defined in a separate issue, though perhaps developed in tandem because of overlap between the features?)
4. After forking, the first entry in the history of the new phenotype makes it clear that is was "forked from PH1234".
5. A statement that the phenotype was created as a fork of PH1234 should also appear near the top of the new phenotype after the version information.
6. The "my collection" page could show "people who forked my phenotypes".
7. A phenotype should also link to forks that have been made of it somehow. What section to put that in needs to be decided.
8. I think that any information about forks (on either side) should show regardless of phenotype version. e.g. if PH1234 version 456 was forked to create a new phenotype, that information should show up not just in version 456 but also version 455. And if a new version 457 is created, it should show up there as well. (The information should show version to clarify this. (i.e. "PH1234/456 was forked to create PH7890 on 12/02/2024")). I think the information would be too hidden if it was only shown on the one specific version that was forked.