Fix #99203

create "real" TextDocument when opening a notebook or when adding cells, don't create them again when the renderer makes models

add eol to IMainCellDto, no more attach/dettach text document but use the actual (sync'd) document or a fallback cell document

add storageUri and globalStorageUri to ExtensionContext, https://github.com/microsoft/vscode/issues/101857

* notebooks: pipe renderer API postmessages to the renderer itself

Previously the postMessage on acquireNotebookRenderer API was just
a proxy to the global vscode postmessage. Now, it's linked to the
renderer and will cause an optional `onDidReceiveMessage` method on
the renderer to be called.

The message still _also_ goes to the global webview message handling
for advanced use cases, but this change allows the webview<->renderer
communication to be more nicely contained
and separate for most use cases.

* wip

* fixup! pr comments

Some API changes:

 - I changed the second param of NotebookOutputRenderer.render to a
   `NotebookRenderRequest` since we were up to four parameters already.
 - The request contains a unique `outputId`, which is generated when
   output is first created or restored (the ID is not stable if a
	 notebook is closed and reopened)
 - I changed the renderer events to `onDidCreateOutput` and
   `onWillDestroyOutput` since they're for outputs, not cells.
 - Additionally, they're called with objects that contain the output
   ID to render.

notebooks - wire up onDidChange event from notebook providers, fyi @rebornix,  https://github.com/microsoft/vscode/issues/96403