feat: add redraw builtin key-binding, unbound

When opening a browser, GNOME things have a tendency to spew messages to stderr
which corrupts the gh-dash display.  Nothing made it possible to get a display
which then restored the output, the entry area, etc.

A screen redraw command is useful for "something has happened, it shouldn't
have, we know it shouldn't have, but that's life, go ahead and redraw please".
This has traditionally been bound to Ctrl-L; but unlike #565 it
is not bound in this commit, leaving folks to opt-in via local configuration.

The bubbletea internals appear to have a `repaintMsg{}` but I couldn't figure
out how to just send that.  The lightest-weight option I found was to batch
together `ExitAltScreen` and `EnterAltScreen`.  This causes a very brief
flicker which ... is also traditional and I'm accepting it as "shows positive
feedback that the keystroke was acted upon" rather than a bug.

With this, `gh-dash` can be safely used to `o`pen issues in a browser without
then needing to quit and restart, because it offers a recovery mechanism.

Author: philpennock

ui/keys/keys.go

@@ -20,6 +20,7 @@ type KeyMap struct {
 	OpenGithub    key.Binding
 	Refresh       key.Binding
 	RefreshAll    key.Binding
+	Redraw        key.Binding
 	PageDown      key.Binding
 	PageUp        key.Binding
 	NextSection   key.Binding
@@ -247,6 +248,8 @@ func rebindUniversal(universal []config.Keybinding) error {
 			key = &Keys.Refresh
 		case "refreshAll":
 			key = &Keys.RefreshAll
+		case "redraw":
+			key = &Keys.Redraw
 		case "pageDown":
 			key = &Keys.PageDown
 		case "pageUp":

ui/ui.go

@@ -246,6 +246,11 @@ func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 			m.setCurrentViewSections(newSections)
 			cmds = append(cmds, fetchSectionsCmds)
 
+		case key.Matches(msg, m.keys.Redraw):
+			// can't find a way to just ask to send bubbletea's internal repaintMsg{},
+			// so this seems like the lightest-weight alternative
+			return m, tea.Batch(tea.ExitAltScreen, tea.EnterAltScreen)
+
 		case key.Matches(msg, m.keys.Search):
 			if currSection != nil {
 				cmd = currSection.SetIsSearching(true)