[XMA] Added multiple versions of XMA decoders

- Fake: No decoding
- Master: 1:1 from base version of Xenia
- Old: Master with improvements
- New: Completely new decoder with better stability (but not compability)

Co-authored-by: Herman S. <429230+has207@users.noreply.github.com>

src/xenia/apu/xma_context_old.h

@@ -66,6 +66,10 @@ class XmaContextOld : public XmaContext {
   void Decode(XMA_CONTEXT_DATA* data);
   int PrepareDecoder(uint8_t* packet, int sample_rate, bool is_two_channel);
 
+  // This method should be used ONLY when we're at the last packet of the stream
+  // and we want to find offset in next buffer
+  uint32_t GetPacketFirstFrameOffset(const XMA_CONTEXT_DATA* data);
+
   // uint32_t decoded_consumed_samples_ = 0; // TODO do this dynamically
   // int decoded_idx_ = -1;