1cfa82ca57
* Add CustomPopupPlacement API * Add Placement="Custom" support for Flyout, ToolTip and ContextMenu controls as well * Adjust some API changes * Add Avalonia.Controls.Primitives.IPopupHost.ConfigurePosition breaking change * Extract new types into separated files * Fix build after merge conflict * Adjust nupkg.xml * Dispose property subscriptions after popup is closed, avoiding flickering * Adjust API to be more future proof and add new parameters. * Add new ContextRequestedEventArgs overload while I am on it