Fixes #106415

Support for these was added in electron 11

* Make default text editor replace existing editors for resource

Fixes #111474

This ports the logic that we previouly had for custom editors to the generic open with flow: https://github.com/microsoft/vscode/blob/f0bb23ca02f320816219017234e412caa425851e/src%2Fvs%2Fworkbench%2Fcontrib%2FcustomEditor%2Fbrowser%2FcustomEditors.ts#L281

* Add a new `getEditorsForResource` helper method to editor service

This adds a `IEditorService.getEditorsForResource` method that returns all editors associated with a given resource. I've adopted this for custom editors and notebooks

* Making suggested changes

* Add unit tests for findEditors

This setting is no longer used

- Add error notification if opener throws an exception
- Add public facing id to openers. This is used in settings
- Add intellisense for the opener id setting

* Snippets and Auto-closing pairs play nicer

* move to DisposableStore

closes #114303

Do not show "Cannot reconnect. Please reload the window" if the cause is a handled RemoteAuthorityResolverError

https://github.com/microsoft/vscode-codicons/commit/f0dd0920eea259d83e56191fe85af4550cf7a843