text-layout and selection is a Struggle in egui

• tables want you to state the height of each row before drawing it, so we have to manually construct the text widgets and compute max height to get rows that grow to fit

• labels are non-interactive, and I think you have to use an uneditable text_edit (one that points to an &str instead of a String)? But then I don't think for something like a table you can multi-select across all the items, like you can in a browser.

For a while I was doing the "immutable text_edit" thing but I regressed that when cleaning up table layout. I can put it back but I'm starting to wonder if I should just be making more the tables into one giant text-area so that you can copy the whole table out easily?