Major changes:
- Remove Gate knob from effects, effectively hard coding its value to zero
- Replace effect RMS calculations with a more efficient way of detecting silent buffers
- Only perform silent buffer detection when `ProcessStatus::ContinueIfNotQuiet` is returned from a plugin AND auto-quit is enabled
Minor changes:
- Remove gate from presets
- Remove gate from .mmp projects
- Move `Effect::processorCount()` to `LadspaEffect`
- Rename `Effect::checkGate` to `Effect::handleAutoQuit`
- Adjust silence threshold for better compatibility with old RMS calculations
- Remove some unnecessary methods from `Effect`
- Reset quiet buffer count in `stopRunning`
- Use positive name for auto-quit boolean
- Simplify `m_autoQuitEnabled` initialization
