feat(http2): configure HTTP/2 frame size in the high-level builders too (#2214)

Oops, I missed this in #2211.

src/client/mod.rs

@@ -1040,6 +1040,16 @@ impl Builder {
         self
     }
 
+    /// Sets the maximum frame size to use for HTTP2.
+    ///
+    /// Passing `None` will do nothing.
+    ///
+    /// If not set, hyper will use a default.
+    pub fn http2_max_frame_size(&mut self, sz: impl Into<Option<u32>>) -> &mut Self {
+        self.conn_builder.http2_max_frame_size(sz);
+        self
+    }
+
     /// Sets an interval for HTTP2 Ping frames should be sent to keep a
     /// connection alive.
     ///