fix: column default_sort_order respected when resorting

[machow]

addresses #25 by adding a Column.default_sort_desc property. This means that...

• The Props (Table data) class still handles setting the initial sort order for columns.
• Columns now have the data to say what to do when a column is unsorted, and then sort is clicked.
  • e.g. Column A set to default to ascending order, AND it is initially sorted. If a person clicks Column B, it unsets the Column A sorting. Then, when they click Column A again, it should use the specified default and first do ascending.

Here's a demo of the fix using https://pr-26--react-tables-preview.netlify.app/get-started/controls-sorting#default-sort-order

Initial

click sort by year

click sort by species