Details:
* Switched SDL audio mutex to RW lock. This fixes games that continiously call SetVolume in a different thread (like Ghostbusters)
* Added contition to buffer audio packets independent of video packets. This fixes choppy audio across many games.
* Increased the number of audio frame buffers from 2 to 4. Just in case.
* Migrated to std::jthread and std::mutex from pthreads.
* Fixed a race condition with joins on avplayer close that caused a crash.
* sceKernelOpen truncate is not neccesary
* fixup scePthreadCondSignal
* dummy error , ime dialogs stubbed
* sceErrorDialog implemenation (no ui)
* small fix in sceSaveDataGetEventResult and sceAppContentTemporaryDataMount2.
* ime dialog structs and functions definations
* added stubbed avplayer
* Open folder should be first on context menu
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Co-authored-by: raziel1000 <ckraziel@gmail.com>