Web API for tunnels
Part of #81388

Fixes #83209

**Bug**
The extension page currently uses hardcoded height values for the header. This height breaks if the extension is recomended

**Fix**
Use flex layout instead

For #88313

Also log updateGraph on `completions.execute` instead of as its own event

We are also exproting other values/types, so use a named export instead

Fixes #88313

* Add call hierarchy support for TypeScript 3.8

* Add version dependent registration for call hierarchy provider

* Revert TS version, PR feedback

and fix related bugs

Fixes #88060

Part of #88244

Fixes #88059

fixes #88240

Part of #88060

We allow tunneling for extensions regardless of whether they are in a local or remote extension host.

Fixes #88245

So far, file editors have reported isDirty() === false when auto save was enabled e.g. to avoid showing dirty indicators. With the advent of custom editors, this needs to be cleaned up. The new method isSaving() serves as a hint that an editor can be dirty but in the process of being saved. As such, we can decide to hide the dirty indicator in that case. But in other cases we may want to know if the editor is dirty or not, even if auto saved.

callstack and bp editor contributions, to fix tests