[State] Presets with state chunk is not supported in our .FXB generator/parser

[p0nce]

• [x] Can parse .fxp with chunk and non-chunks in presetbank
• [x] V2 Dplug chunks necessitate the --state flag in presetbank.
• [ ] Can create .fxb bank made of presets with state chunks
• [ ] Can parse such .fxb even if we generated it with presetbank

For now: presets with empty state will work, as a workaround.

[p0nce]

Would be clearer to have a lib that abstract presets in the first place, instead of having this weird PresetBank that is always with a Client, that owns exactly one.