Fix hevc decode error "Could not find ref with POC" (#9960)

1. Dropping frames can cause this error, reset encoder when this
   happens.
2. There are some logic error for clear video queue, because video queue
   message is not cleared. This need to be fixed.

Signed-off-by: 21pages <sunboeasy@gmail.com>

libs/scrap/src/common/hwcodec.rs

@@ -15,7 +15,7 @@ use hbb_common::{
 };
 use hwcodec::{
     common::{
-        DataFormat,
+        DataFormat, HwcodecErrno,
         Quality::{self, *},
         RateControl::{self, *},
     },
@@ -31,6 +31,7 @@ const DEFAULT_PIXFMT: AVPixelFormat = AVPixelFormat::AV_PIX_FMT_NV12;
 pub const DEFAULT_FPS: i32 = 30;
 const DEFAULT_GOP: i32 = i32::MAX;
 const DEFAULT_HW_QUALITY: Quality = Quality_Default;
+pub const ERR_HEVC_POC: i32 = HwcodecErrno::HWCODEC_ERR_HEVC_COULD_NOT_FIND_POC as i32;
 
 crate::generate_call_macro!(call_yuv, false);