Deleting multiple files through explorer invokes the event listeners per file

[deepak1556]

When testing #85929

Steps to reproduce:

1. Register delete event listeners

vscode.workspace.onWillDeleteFiles((e : vscode.FileWillDeleteEvent) => {
	const p = new Promise((resolve) => {
		setTimeout(() => resolve(), 10000);
	});
	e.waitUntil(p);
	console.log(e.files.length);
});

vscode.workspace.onDidDeleteFiles((e : vscode.FileDeleteEvent) => {
	console.log('DELETING...');
	e.files.forEach(file => console.log(file));
});

2. Select multiple files from the explorer with Cmd+Click and delete using context menu.

3. Expect to receive single event fire for all the files but instead the listener is fired individually for each file being deleted.

Output:

1
1
DELETING...
<Object>
DELETING...
<Object>

[isidorn]

The issue is that the file-explorer calls the textFileService per resource. To tackle this we should introduce a bulk call in the textFileService.

[isidorn]

This should actually be fixed now with the PR that introduces bulk operations