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.

Cargo.lock

@@ -2564,6 +2564,7 @@ dependencies = [
  "soulseek-rs-lib",
  "tempfile",
  "toml",
+ "unicode-truncate",
 ]
 
 [[package]]