share undo stack between text models in a notebook. the undo stack is not shared with notebook itself yet due to #98750.

For #98746

Updated to take the latest distro changes.

Fix debug icon. Use Codicons instead of text

Fixes microsoft/vscode-internalbacklog#995

This reverts commit 40559425.

From https://github.com/microsoft/vscode/pull/98131#issuecomment-635104095

Fixes #98668

This reverts commit a2bc061b.

Revert "merge metadata into local extension"

This reverts commit b354b435.

load custom renderers when reloading from backup.

This reduces the use of the ipc module

Updated to take the latest distro changes.

* Move webview's use of setIgnoreMenuShortcuts to main processes

Part of #95955

Switches from calling `setIgnoreMenuShortcuts` on the renderer to calling it on the main thread

* Use channels for communication instead of ipc

* Cleanup ipc implementation

* Rename webviewMainService -> WebviewManagerService

* Add property default show context value proeprty

* Change precedence

defaultShowContextValue takes precedence
over
reusePriorSearchConfiguration

* Respect 0 as a default context lines value
Co-authored-by: NJackson Kearl <jakearl@microsoft.com>

highly scoped implementation for select boxes and dropdowns that need it
fixes #90729
fixes #93415