[PATCH v2 0/7] MR7409: mp3dmod: Implement GetInputCurrentType and GetOutputCurrentType

[Brendan McGrath (＠redmcg)]

This MR implements the following APIs in `mp3dmod`:
- `GetInputCurrentType`
- `GetOutputCurrentType`

It also adds checks to various APIs for an invalid stream and fixes a potential resource leak in `SetOutputType`.

This is in preparation for adding an `IMFTransform` interface to the MP3 decoder as detailed here:

https://learn.microsoft.com/en-us/windows/win32/medfound/windows-media-mp3-d...

--
  v2: mp3dmod: Fix leak of previous outtype.
      mp3dmod: Implement GetOutputCurrentType.
      mp3dmod: Implement GetInputCurrentType.
 
https://gitlab.winehq.org/wine/wine/-/merge_requests/7409