feat: add album keyboard shortcuts (#16442)

* 15712: Added keyboard shortcuts for opening add to album modal and highlighting/selecting an album to add to.

* 15712: Re-factored logic from template code into script. Extracted new album button into separate cmponent.

* 15712: Document new keyboard shortucts now that they work everywhere.

* 15712: Extract some constants/helper functions.

* 15712: Missing comma.

* 15712: Pulled logic out into separate unit testable class.

* 15712: Added a unit test.

* 15712: Move the modal back up to keep the github PR happy.

* 15712: PR feedback - renamed typescript files and switch to class bind directive.

* 15712:Move selection modal into correct package.

* 15712: Better naming of module and files.

web/src/lib/components/shared-components/show-shortcuts.svelte

@@ -33,6 +33,8 @@
         { key: ['f'], action: $t('favorite_or_unfavorite_photo') },
         { key: ['i'], action: $t('show_or_hide_info') },
         { key: ['s'], action: $t('stack_selected_photos') },
+        { key: ['l'], action: $t('add_to_album') },
+        { key: ['⇧', 'l'], action: $t('add_to_shared_album') },
         { key: ['⇧', 'a'], action: $t('archive_or_unarchive_photo') },
         { key: ['⇧', 'd'], action: $t('download') },
         { key: ['Space'], action: $t('play_or_pause_video') },