[ExAPI] Added play and stop sound api for third-party TTS integration
Doc: https://live2d.pavostudio.com/doc/en-us/exapi/api-list/
Github: https://github.com/pavostudio/ExAPI
[Main App] Optimized scene data saving; note that this data update is irreversible
[Main App] Improved handling when Workshop models are missing at startup, automatically switching to backup models
[Main App] Optimized playlist to ensure equal probability for all items when selecting random playback
[Control Panel] Nearly all sliders can now be reset by clicking the value
[Control Panel] Holding the left Ctrl key and clicking a slider value now brings up an input box for precise adjustment
[Control Panel] Toggle buttons can now be changed directly by clicking (previously only draggable)
[Control Panel] Workshop details page now displays user tags