selectable text option

Add a selectable text option to various note views. We don't want
selection events to interfere with back drag, so this is the first step
toward ensure back drag works.

Vertical scrollviews also interfere with back drag, so we'll still need
a way to compose gestures. It's not clear if this is currently possibly
with egui (union of responses somehow maybe?)

Signed-off-by: William Casarin <jb55@jb55.com>

src/ui/timeline.rs

@@ -90,6 +90,7 @@ fn timeline_ui(ui: &mut egui::Ui, app: &mut Damus, timeline: usize, reversed: bo
                         let textmode = app.textmode;
                         let resp = ui::NoteView::new(app, &note)
                             .note_previews(!textmode)
+                            .selectable_text(false)
                             .show(ui);
 
                         if let Some(action) = resp.action {