Properly reset editor.lineNumbers after disabling zen mode

[jeanp413]

This PR fixes #90240

Uses a Set to remember all the editors we have hidden line numbers for. Not sure if it's safe to call updateOptions on disposed editor widgets (this could happen if we have multiple editor groups and we close any of them)

cc @isidorn

[isidorn]

Seems to work great. Merging in. Thanks a lot for this PR.
As for updating options on disposed editor widgets that also seems to work fine. @bpasero I could not detect a way to see if the editor is disposed, when do you exactly dispose them?

[bpasero]

@isidorn @jeanp413 not a big fan of how this ends up adding a new field to the layout.ts class which is only used by zen mode. Why can this not be added to the transitionDisposables set that is called each time zen mode changes? There should be a disposable for each editor that gets the line number updated, no?

As for IEditor, let me copy some JSDoc that maybe explains better how to listen for disposal:

vscode/src/vs/editor/common/editorCommon.ts

Lines 248 to 258 in 9a81eb3

	export interface IEditor {
	/**
	* An event emitted when the editor has been disposed.
	* @event
	*/
	onDidDispose(listener: () => void): IDisposable;
	/**
	* Dispose the editor.
	*/
	dispose(): void;

Upon disposal, simply remove the entry from the transition disposables.

[isidorn]

Yeah, adding to the tranisitionDisposables makes better sense.
And we could listen to the dispose event
@jeanp413 sorry for preemptively mering this. Just let me know if you will provide an additional pr that tackles Ben suggestions, if not I can also look into this. Thanks

[jeanp413]

@isidorn Sure I'll create another PR to tackle bpasero's feedback