DispatcherTimer should inherit IDisposable

[lindexi]

Avalonia/src/Avalonia.Base/Threading/DispatcherTimer.cs

Line 13 in ec9af9c

public class DispatcherTimer

As this code that DispatcherTimer is the property _timer and it can be disposed in the destructor .

Avalonia/src/Avalonia.Base/Threading/DispatcherTimer.cs

Line 58 in ec9af9c

if (_timer != null)

But it cant be disposed in DispatcherTimer that we should call the Stop to dispose it.

And I find another bug in DispatcherTimer like wpf. If the dever use DispatcherTimer and give the zero interval and dont write the Tick it will use 100% cpu in a thread.

I think it needs to check if the Tick is null and when the Tick is null, it will not really run.

[kekekeks]

Dispatcher timers are now tracked by dispatcher rather than the platform code