Interleave sending and receiving of packets to reduce rx latency (#515)

* Interleave sending and receiving of packets to reduce latency in receiving of packets

* Add patch to CtapUsbSyscallDriver

* Minor tweaks from review

* Log when overwritting an existing reply

* Only log when 'debug_ctap' is enabled

* Make ctap mod public, as per review

* Rename send_or_recv to send_and_maybe_recv

* fix typo

* Don't process packets on other transport while doing keepalive

* Don't process packets on other transport while doing keepalive

* More accurately determine if reply has finished

* Move comment closer to appropriate location

* Add tests for canceling keepalive packets

* Added a TODO for kaczmarczyck re ctap module being public

* remove the unnecessary sleep()s

* undo messed up commit

* address pylint warnings

* Fix merge mess up, and patch fido2 Usage Page

* Fix up completely borked merge

* Remove patch to FIDO usage, after #523.

* remove obsolete aspects to diff

Co-authored-by: kaczmarczyck <43844792+kaczmarczyck@users.noreply.github.com>

src/ctap/hid/send.rs

@@ -32,6 +32,14 @@ impl HidPacketIterator {
     pub fn none() -> HidPacketIterator {
         HidPacketIterator(None)
     }
+
+    pub fn has_data(&self) -> bool {
+        if let Some(ms) = &self.0 {
+            ms.finished()
+        } else {
+            false
+        }
+    }
 }
 
 impl Iterator for HidPacketIterator {
@@ -94,6 +102,15 @@ impl MessageSplitter {
             dst_len
         }
     }
+
+    // Is there more data to iterate over?
+    fn finished(&self) -> bool {
+        let payload_len = self.message.payload.len();
+        match self.seq {
+            None => true,
+            Some(_) => self.i < payload_len,
+        }
+    }
 }
 
 impl Iterator for MessageSplitter {