Make history service work with debounced editor events

https://github.com/microsoft/vscode/pull/163845 was an attempt to defer events for history service processing but it caused https://github.com/microsoft/vscode/issues/173109 so I reverted it. https://github.com/microsoft/vscode/issues/173111 is a related issue where disposing a debounced event emitter looses events when disposed before the timeout is hit. Even if https://github.com/microsoft/vscode/issues/173111 is addressed, we process editor events in a way that we ask the editor for its selection and when events are debounced, the editor may no longer be what we expect. https://github.com/microsoft/vscode/blob/43db9d2d06df4ff7b7f029b30bbdaea51b8f16f5/src/vs/workbench/services/history/browser/historyService.ts#L1479 https://github.com/microsoft/vscode/blob/43db9d2d06df4ff7b7f029b30bbdaea51b8f16f5/src/vs/workbench/services/history/browser/historyService.ts#L1493 So if we want to bring back debouncing to the history service, we cannot ask the editor at all for any information.