Fetch wheel metadata by async range requests on the remote wheel (#301)

Use range requests and async zip to extract the METADATA file from a
remote wheel.

We currently only cache when the remote says the remote declares the
resource as immutable, see
https://github.com/06chaynes/http-cache/issues/57 and
https://github.com/baszalmstra/async_http_range_reader/pull/1 . The
cache is stored as json with the description omitted, this improve cache
deserialization performance.

crates/puffin-client/tests/remote_metadata.rs

@@ -0,0 +1,28 @@
+use std::str::FromStr;
+
+use anyhow::Result;
+use tempfile::tempdir;
+use url::Url;
+
+use distribution_filename::WheelFilename;
+use puffin_client::RegistryClientBuilder;
+
+#[tokio::test]
+async fn remote_metadata_with_and_without_cache() -> Result<()> {
+    let temp_cache = tempdir().unwrap();
+    let client = RegistryClientBuilder::default()
+        .cache(Some(temp_cache.path().to_path_buf()))
+        .build();
+    // The first run is without cache (the tempdir is empty), the second has the cache from the
+    // first run
+    for _ in 0..2 {
+        let url = "https://files.pythonhosted.org/packages/00/e5/f12a80907d0884e6dff9c16d0c0114d81b8cd07dc3ae54c5e962cc83037e/tqdm-4.66.1-py3-none-any.whl";
+        let filename = WheelFilename::from_str(url.rsplit_once('/').unwrap().1).unwrap();
+        let metadata = client
+            .wheel_metadata_no_index(&filename, &Url::parse(url).unwrap())
+            .await
+            .unwrap();
+        assert_eq!(metadata.summary.unwrap(), "Fast, Extensible Progress Meter");
+    }
+    Ok(())
+}