usb-hid: Simplify API.

- Renamed structs to HidReaderWriter, HidReader, HidWriter.
- Removed unused const generics on `State`.
- Simplified generics on `HidReaderWriter`.
  The class type previously was `HidClass<D, Driver<'d, USBD>, ReportReader<'d, Driver<'d, USBD>, OUT_N>, IN_N>`
  It's now `HidClass<D, Driver<'d, USBD>, IN_N, OUT_N>`. Note that the driver type `Driver<'d, USBD>` is no longer repeated.
- Constructors are now: `HidWriter::new()` for IN-only, `HidReaderWriter::new()` for IN+OUT. No complicated bounds.
- HidReaderWriter has all the methods from HidReader, HidWriter.

examples/nrf/src/bin/usb_hid_mouse.rs

@@ -13,7 +13,7 @@ use embassy_nrf::usb::Driver;
 use embassy_nrf::Peripherals;
 use embassy_usb::control::OutResponse;
 use embassy_usb::{Config, UsbDeviceBuilder};
-use embassy_usb_hid::{HidClass, ReportId, RequestHandler, State};
+use embassy_usb_hid::{HidWriter, ReportId, RequestHandler, State};
 use futures::future::join;
 use usbd_hid::descriptor::{MouseReport, SerializedDescriptor};
 
@@ -52,7 +52,7 @@ async fn main(_spawner: Spawner, p: Peripherals) {
     let mut control_buf = [0; 16];
     let request_handler = MyRequestHandler {};
 
-    let mut control = State::<5, 0>::new();
+    let mut control = State::new();
 
     let mut builder = UsbDeviceBuilder::new(
         driver,
@@ -65,7 +65,7 @@ async fn main(_spawner: Spawner, p: Peripherals) {
     );
 
     // Create classes on the builder.
-    let mut hid = HidClass::new(
+    let mut writer = HidWriter::<_, 5>::new(
         &mut builder,
         &mut control,
         MouseReport::desc(),
@@ -94,7 +94,7 @@ async fn main(_spawner: Spawner, p: Peripherals) {
                 wheel: 0,
                 pan: 0,
             };
-            match hid.input().serialize(&report).await {
+            match writer.write_serialize(&report).await {
                 Ok(()) => {}
                 Err(e) => warn!("Failed to send report: {:?}", e),
             }