This documents the current thinking on the custom editor api. The current api proposal is not actually implemented yet

Fixes #80375

Fixes #69785

Fixes #69785

Fixes #82896

Fixes #82128

This reverts commit afa911d9.

Part of #80375

fix #82203

Fixes #81709

Fixes https://github.com/microsoft/vscode/issues/81712 and https://github.com/microsoft/vscode/issues/81736

These features are not working in many cases and the api around them will likely change significantly

#81131

Split out from #77131

The current webview editor api is very procedural. This model has some problems when it comes to supporting editing resources, but actually does make a lot of sense for webviews that aren't backed by real file system resources. For example, if you have a webview that edits some document in the cloud, you should not be required to implement a custom file system provider just to enable basic saving.

This change moves the `onWillSave` and `webviewEditorState` properties back onto `WebviewPanel` instead of keeping them specific to `WebviewEditor`. The save implementation does not fully work yet, as the will require #81521

and update documentation for it. Part of #80375

For #81131

We had trouble coming up with cases where extensions could actually reliably dispose of the resolved uri

Introduced DebugSessionOptions passed to debug.startDebugging which
encapsulated DebugConsoleMode to control this behavior.

Fixes #80401