examples: add example using ArchiveIterator

Useful for running ArchiveIterator under valgrind, e.g. to check for
memory leaks.

examples/uncompress_iterator.rs

@@ -0,0 +1,26 @@
+// SPDX-License-Identifier: MIT OR Apache-2.0
+
+use argh::FromArgs;
+use compress_tools::*;
+
+#[derive(FromArgs, PartialEq, Eq, Debug)]
+/// Top-level command.
+struct TopLevel {
+    /// source path
+    #[argh(positional)]
+    source_path: String,
+}
+
+fn main() -> compress_tools::Result<()> {
+    let cmd: TopLevel = argh::from_env();
+
+    let source = std::fs::File::open(cmd.source_path)?;
+
+    for content in ArchiveIterator::from_read(source)? {
+        if let ArchiveContents::StartOfEntry(name, stat) = content {
+            println!("{name}: size={}", stat.st_size);
+        }
+    }
+
+    Ok(())
+}