feat(tui): scroll long result names and page through results

Closes #55.

While [2] Results is focused the Info pane describes the highlighted
result, so a truncated path can be read in full. h/l (or the arrow keys)
scroll the filename column by display cells, 0 and $ jump to either end
of the highlighted name, and Home/End, g/G, PgUp/PgDn and Ctrl-f/b/d/u
move through the list; the same keys work while a filter is being typed.

Ctrl chords are no longer read as their bare letter: outside [2] they do
nothing, where before Ctrl-d deleted a search and Ctrl-c opened rooms.
Space after a filter that matches nothing no longer indexes an empty
list.

soulseek-rs/src/ui/panes/mod.rs

@@ -8,8 +8,12 @@ mod searches_pane;
 
 pub use browse_pane::render_browse_pane;
 pub use chat_pane::render_chat_pane;
-pub use download_info_pane::{render_download_info_pane, selected_transfer};
+pub use download_info_pane::{
+    InfoSubject, render_download_info_pane, selected_transfer,
+};
 pub use downloads_pane::render_downloads_pane;
-pub use results_pane::{ResultsPaneParams, render_results_pane};
+pub use results_pane::{
+    ResultsPaneParams, name_end_offset, render_results_pane,
+};
 pub use rooms_pane::render_rooms_pane;
 pub use searches_pane::render_searches_pane;