reopen #237540

Please consider reopening and elevating https://github.com/microsoft/vscode/issues/237540, as the programming field has shifted dramatically since it was last considered.

In the last year and a half, a significant portion of development has shifted to agent-first coding, eliminating the need for many developers to have eyes on their code at all times.

For these developers, during this phase of the development process, the editor window remains a blank but non-hideable waste of screen space. Developers need a way to quickly toggle this from between visible and hidden state.