[python] Tutorial notebook for the new-shape feature

[johnkerl]

Issue and/or context: As tracked on issue #2407 / [sc-51048].

Note that the intended Python and R API changes are all agreed on and finalized as described in #2407.

Changes:

• Notebook material for Python. (R material will be a separate PR.)
  Notes for Reviewer:

• The Python material is ready for review.

• Handy link for reviewers:

  • https://github.com/single-cell-data/TileDB-SOMA/blob/kerl/new-shape-notebook-and-vignette/apis/python/notebooks/tutorial_soma_shape.ipynb

• I'm working on the R material.

[johnkerl]

Converting to draft while I do some underwork as I noted above when I said

... update: gurg, those are a lot of files. I definitely think I want to split out a separate PR, wherein I make the data dirs .tgz files which our notebooks extract for use.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 85.40%. Comparing base (33b104c) to head (017ea32).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3294      +/-   ##
==========================================
+ Coverage   85.29%   85.40%   +0.10%     
==========================================
  Files          52       52              
  Lines        5517     5517              
==========================================
+ Hits         4706     4712       +6     
+ Misses        811      805       -6     

Flag	Coverage Δ
python	85.40% <ø> (+0.10%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Components	Coverage Δ
python_api	85.40% <ø> (+0.10%)	⬆️
libtiledbsoma	∅ <ø> (∅)

[nguyenv]

Just have some minor suggestions. Thank you for the link to the notebook; it was very useful.

[johnkerl]

Merging this round of changes ... @aaronwolen let me know if you have any post-merge feedback and I'm happy to take a follow-on.

Also I'll send the corresponding Academy PRs your way 🙏