miniaudio file name hashing fix

[a740g]

This PR works around miniaudio's file name hashing which causes the following issues:

1. When multiple files are extracted (e.g., from a game data archive) into the same temporary file (e.g., temp.wav) and loaded sequentially, all files are resolved to the first-loaded sound due to the static file name.

2. The MIDI file decoder allows user-defined SoundFonts (.sf2). However, reloading the same MIDI file with a different SoundFont causes a conflict due to file name hashing. For example: If MIDI file A.mid is loaded with SoundFont A.sf2 and later with B.sf2, playback defaults to the first-loaded SoundFont (A.sf2), even if B.sf2 is specified.

Additionally, _MEMSOUND now works correctly with fully decoded MEMORY sounds, expanding its functionality.

Quality of life improvements:

1. Removed usage of unsafe C macros.
2. Eliminated reliance on ma_decoder to simplify audio library.

Special thanks to @mkilgore for proposing the workaround and providing the original implementation.

[mkilgore]

Thanks for turning this into a full-fledged solution :)