Add editing for presets

[livviest]

Is your feature request related to a problem?

Sometimes I want to remove, add, or change a sound for a preset. Since there's no edit/update functionality, first I have to create a new preset and then delete the old one. This seems a little clunky.

Describe the solution you'd like

My proposal is twofold:

1. Add an edit button for each preset on the Presets page that, when selected, presents a list of the sounds selected for the preset. From here the user may adjust the volume or remove individual sounds.

   • Additionally, there could be an "Add sound" button at the bottom of the list that would simply navigate over to the Library tab.

2. If a preset is actively playing while on the Library tab and sounds are added/adjusted, pressing the save button should present the user with the option of overwriting/updating the preset, or saving as a new preset.