Compute spectrogram automatically

Previously you had to precompute the spectrogram and pass via sxx prop.
Now if sxx is not passed, it will call Rust coded compiled in Web Assembly to compute the spectrogram for you.
Therefore, you can now also pass the following spectrogram props:

• sampleRate
• n_fft
• win_length
• hop_length
• f_min
• f_max
• n_mels
• top_db

You can also now specify some default view values and settings

• startTimeInitial and endTimeInitial allows you to pick a range to zoom into
• playbackSpeedInitial and playheadModeInitial will override the initial setting in the "Settings" UI of the player.