feat(lib): carry audio attributes in browse and folder listings

A browse listed each file as a name and a size, so a searcher who saw a
bitrate in a search reply lost it the moment they opened the sharer's
files. Listings (codes 5 and 37) now carry each file's attributes the
way Nicotine+ sends them, as a SharedFileEntry with name, size and
attributes in place of the (name, size) pair; the CLI's browse record
gains bitrate and duration, and the daemon protocol moves to version 2
for the new listing shape.

soulseek-rs/src/commands/social.rs

@@ -61,13 +61,15 @@ pub fn browse(ctx: &Ctx, args: &BrowseArgs) -> CliResult {
 
     let mut files = 0usize;
     for directory in &directories {
-        for (basename, size) in &directory.files {
+        for file in &directory.files {
             files += 1;
             ctx.out.emit(&BrowseRecord {
                 user: args.user.clone(),
                 directory: directory.name.clone(),
-                path: full_path(&directory.name, basename),
-                size: *size,
+                path: full_path(&directory.name, &file.name),
+                size: file.size,
+                bitrate: file.attribute(super::transfer::ATTR_BITRATE),
+                duration: file.attribute(super::transfer::ATTR_DURATION),
             });
         }
     }