Feature 185 shiny test 2

[DarianGill]

DRAFT. NOT READY FOR REVIEW

What

Begins work on #185 by adding two more holistic functionality tests via shinytest2:

1. To test that you can navigate from Home to Plots and filter by a community concept via inspection in the detail panel and
2. That tests the ability to filter the plot table by project, open a plot on the map, and then search for and disambiguate a plot author observation code there

Why

So we can make progress towards protecting functionalities against regression now that more features are coming online.

How

• Uses shinytest2 to run tests via testthat::test()
• Captures initial state in json files
• Programmatically manipulates state and checks ui output for the scenarios above

Testing and Documentation