Speed up display configuration and break up configuration code to be less monolithic

[waydabber]

Reconfiguration could be improved to be a bit more granular and quicker in response to display configuration changes. Now on every change all displays are rechecked. It's a fast process but might be even faster.

[waydabber]

Some code ideas provided by @Wouter01

import CoreGraphics

public enum Display {
    public static var configurationChanges: AsyncStream<(UInt32, CGDisplayChangeSummaryFlags)> {
        let (stream, continuation) = AsyncStream.makeStream(of: (UInt32, CGDisplayChangeSummaryFlags).self)
        
        let callback: CGDisplayReconfigurationCallBack = { displayID, changeFlags, pointer in
            let this = unsafeBitCast(pointer, to: AsyncStream<(UInt32, CGDisplayChangeSummaryFlags)>.Continuation.self)
            this.yield((displayID, changeFlags))
        }
        
        let context = unsafeBitCast(continuation, to: UnsafeMutableRawPointer.self)
        CGDisplayRegisterReconfigurationCallback(callback, context)
        
        continuation.onTermination = { _ in
            CGDisplayRemoveReconfigurationCallback(callback, context)
        }
        
        return stream
    }
}
extension CGDisplayChangeSummaryFlags: CaseIterable {
    public static var allCases: [CGDisplayChangeSummaryFlags] {
        [.addFlag, .beginConfigurationFlag, .desktopShapeChangedFlag, .disabledFlag, .enabledFlag, .mirrorFlag, .movedFlag, .removeFlag, .setMainFlag, .setModeFlag, .unMirrorFlag]
    }
}

extension CGDisplayChangeSummaryFlags: CustomStringConvertible {
    
    private func singleValueDescription(flag: Self) -> String {
        switch flag {
        case .addFlag: "Add"
        case .beginConfigurationFlag: "Begin Configuration"
        case .desktopShapeChangedFlag: "Desktop Shape Changed"
        case .disabledFlag: "Disabled"
        case .enabledFlag: "Enabled"
        case .mirrorFlag: "Mirror"
        case .movedFlag: "Moved"
        case .removeFlag: "Remove"
        case .setMainFlag: "Set Main"
        case .setModeFlag: "Set Mode"
        case .unMirrorFlag: "Unmirror"
        default: "Unknown"
        }
    }
    
    public var description: String {
        CGDisplayChangeSummaryFlags.allCases
            .filter { contains($0) }
            .map { singleValueDescription(flag: $0) }
            .joined(separator: ", ")
    }
}

[waydabber]

The issue seems to be that macOS sends all kinds of flags that most of the time require almost everything to be updated anyway... Like desktopShapeChanged is almost always sent to all displays indiscriminately when one display mode changes or is rotated, while nothing is sent on changing mode to HDR etc.