Spectrogram UX improvements

[Brollyy]

24

Added a way to resize the column with spectrogram to get both a better look at the image and to allow users to drag it closer to the note editor to check their alignment.

Added caching for spectrogram to make sure we don't re-do expensive calculations unnecessarily when opening a map again or resizing the spectrogram.

Added user settings for customizing the spectrogram, including algorithm used, frequency range and colormap (previously it was always MelScale, 16kHZ, Blues). I've set the defaults to Standard, 11kHz, which seems about the same settings that are used by MMA2 for their spectrogram. I've left Blues as the default colormap for theming, but after testing a few I actually found I prefer Lopora more and I saw that MMA2 uses Plasma.

White bar allows user to change the width of the spectrogram by dragging it:

New section in user settings (only displays after user enables spectrogram):

Using Standard with 11kHz takes a little longer to load initially, but provides much higher resolution, especially with the ability to resize:

[Brollyy]

I still have to test some edge cases for performance (e.g. rapidly changing settings) and waiting on feedback from Waatsu after the last change with the flip. Will let you know once it's ready to be merged.

[Nytilde]

it's no good practise to add something lager than one line within a try-catch code block. just as my recommendation: i would either outsource those parts into a function or apply try-catch only to the part where the error can actually occur.

[Brollyy]

I've implemented option to load the spectrogram in chunks to support longer maps and done some code refactoring for readability in VorbisSpectrogramGenerator.

I've tested all of those changes myself, so it should be fine to merge if you don't see any issues - if anything comes up during beta that I didn't find, I'll fix it then.