- change buffer sizes of medians

- change syncing to be more predictable using I2S_EVENT_TX_DONE
  o also increase DMA length so i2s won't eat up so much processing time
  o ensure at least one chunk is in DMA buffer

components/lightsnapcast/include/snapcast.h

@@ -87,7 +87,7 @@ void codec_header_message_free(codec_header_message_t *msg);
 
 typedef struct wire_chunk_message {
     tv_t timestamp;
-    uint32_t size;
+    size_t size;
     char *payload;
 } wire_chunk_message_t;