fix: memory leak in MainThreadWorkspace

[SimonSiefke]

Fixes a memory leak in MainThreadWorkspace.

Details

When a provider is registered, it is both added to a Map called registeredEditSessionProviders as well as to this._toDispose.

this.registeredEditSessionProviders.set(handle, disposable);
this._toDispose.add(disposable);

However when a provider is unregistered, it is removed from the Map registeredEditSessionProviders, but not from this._toDispose

const disposable = this.registeredEditSessionProviders.get(handle);
disposable?.dispose();
this.registeredEditSessionProviders.delete(handle);

This causes the this._toDispose array to grow over time.

Change

The change is using a DisposableMap, ensuring this._toDispose doesn't grow when registering and unregistering providers.

private registeredCanonicalUriProviders = this._register(new DisposableMap<number, IDisposable>());

Before

When restarting extensions 37 times, the number functions in MainThreadWorkspace.$registerCanonicalUriProvider seems to grow by 3 each time. Entries 10/11:

After

When restarting extensions 37 times, the number functions in MainThreadWorkspace.$registerCanonicalUriProvider stays constant: