Improve API navigation. Structured search documentation.

[delucchi-cmu]

• Breaks out the chunks within the API Reference > Catalog page into their own pages, as the left-hand navigation was getting cumbersome.
• Adds a notebook based on this demo notebook
• Adds notes on polygon search about requiring lsst-sphgeom. Closes Polygon search should mention additional required package #996
• Fix to doc render errors in the dask-messages-guide. Unrelated, but I noticed errors while working on docs.

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[github-actions]

Before [0a02c58]	After [db90ea4]	Ratio	Benchmark (Parameter)
41.1±0.5ms	41.7±0.4ms	1.01	benchmarks.time_polygon_search
25.0±0.1ms	25.1±0.2ms	1	benchmarks.time_box_filter_on_partition
5.78±0.02s	5.77±0.04s	1	benchmarks.time_create_large_catalog
93.3±1ms	93.1±2ms	1	benchmarks.time_kdtree_crossmatch
876±10ms	862±8ms	0.98	benchmarks.time_create_midsize_catalog

Click here to view all benchmarks.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 96.86%. Comparing base (0a02c58) to head (dd875be).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #998   +/-   ##
=======================================
  Coverage   96.86%   96.86%           
=======================================
  Files          54       54           
  Lines        2554     2555    +1     
=======================================
+ Hits         2474     2475    +1     
  Misses         80       80           

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[olivialynn]

The catalog subsections are a game changer; huge fan!