Fullscreen MediaViewer refactor

- Moved media related logic into notedeck instead of the ui crate,
  since they pertain to Images/ImageCache based systems

- Made RenderableMedia owned to make it less of a nightmware
  to work with and the perf should be negligible

- Added a ImageMetadata cache to Images. This is referenced
  whenever we encounter an image so we don't have to
  redo the work all of the time

- Relpaced our ad-hoc, hand(vibe?)-coded panning and zoom logic
  with the Scene widget, which is explicitly designed for
  this use case

- Extracted and detangle fullscreen media rendering from inside of note
  rendering.  We instead let the application decide what action they
  want to perform when note media is clicked on.

- We add an on_view_media action to MediaAction for the application to
  handle. The Columns app uses this toggle a FullscreenMedia app
  option bits whenever we get a MediaAction::ViewMedis(urls).

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

crates/notedeck_columns/src/app.rs

@@ -20,9 +20,12 @@ use enostr::{ClientMessage, PoolRelay, Pubkey, RelayEvent, RelayMessage, RelayPo
 use nostrdb::Transaction;
 use notedeck::{
     tr, ui::is_narrow, Accounts, AppAction, AppContext, DataPath, DataPathType, FilterState,
-    Localization, UnknownIds,
+    Images, JobsCache, Localization, UnknownIds,
+};
+use notedeck_ui::{
+    media::{MediaViewer, MediaViewerState},
+    NoteOptions,
 };
-use notedeck_ui::{jobs::JobsCache, NoteOptions};
 use std::collections::{BTreeSet, HashMap};
 use std::path::Path;
 use std::time::Duration;
@@ -365,12 +368,43 @@ fn render_damus(
         render_damus_desktop(damus, app_ctx, ui)
     };
 
+    fullscreen_media_viewer_ui(
+        ui,
+        &mut damus.options,
+        &mut damus.view_state.media_viewer,
+        app_ctx.img_cache,
+    );
+
     // We use this for keeping timestamps and things up to date
     ui.ctx().request_repaint_after(Duration::from_secs(5));
 
     app_action
 }
 
+/// Present a fullscreen media viewer if the FullscreenMedia AppOptions flag is set. This is
+/// typically set by image carousels using a MediaAction's on_view_media callback when
+/// an image is clicked
+fn fullscreen_media_viewer_ui(
+    ui: &mut egui::Ui,
+    options: &mut AppOptions,
+    viewer_state: &mut MediaViewerState,
+    img_cache: &mut Images,
+) {
+    if !options.contains(AppOptions::FullscreenMedia) || viewer_state.urls.is_empty() {
+        return;
+    }
+
+    // Close it?
+    if ui.input(|i| i.key_pressed(egui::Key::Escape)) {
+        options.set(AppOptions::FullscreenMedia, false);
+        return;
+    }
+
+    MediaViewer::new(viewer_state)
+        .fullscreen(true)
+        .ui(img_cache, ui);
+}
+
 /*
 fn determine_key_storage_type() -> KeyStorageType {
     #[cfg(target_os = "macos")]