Updated DNA gramplet ready for review

Would you consider renaming this Gramplet before going public?

Thankfully, this gramplet isn’t actually dealing with raw DNA data, it is charting a very abstract representation of chromosome loci. Sort of like the difference between a histogram of an image and the actual image.

It abstractly charts Chromosomal Segment Matches. How about adapting the name in that direction?

Also, the Help button on the undocked gramplet currently points at the built-in Gramplets page. You might have to rename/move the current documentation. But could you add a gpy.py link to the documentation? I added the following 2 lines below the Gramps version line:

 gramps_target_version='5.1',
 help_url="Addon:DNAgramplet",
 navtypes=["Person"],
 include_in_listing = True,

In my tests, that Navtypes insertion isn’t restricting the Gramples to the People View modes. Not sure what’s wrong there.

Although, come to think of it, this gramplet suits the Relationship Views too. I hope that eventually someday Charts will have an option to graph the direct pedigree (+ spouse) of 2 cousins or create (with unknowns as blank boxes) worksheet charts for something like a “3 cousin 2x removed (up)”. This DNA gramplet would be a great adjunct to such a Chart mode.