Migrate from unsupported paste execCommand in desktop

[deepak1556]

With electron/electron#45277 Electron has dropped support for document.execCommand("paste") to align with browsers. We might be able to get some transition time via electron/electron#45377

This issue captures the existing usages and the work needed to migrate to a web friendly equivalent api.

• Webview https://github.com/microsoft/vscode/blob/main/src/vs/workbench/contrib/webview/browser/webviewElement.ts
• Editor clipboard https://github.com/microsoft/vscode/blob/main/src/vs/editor/contrib/clipboard/browser/clipboard.ts
• Text input actions https://github.com/microsoft/vscode/blob/main/src/vs/workbench/browser/actions/textInputActions.ts (This has a web fallback we can switch to)
• Input clipboard actions https://github.com/microsoft/vscode/blob/main/src/vs/workbench/contrib/codeEditor/electron-sandbox/inputClipboardActions.ts

[bpasero]

Pushed a change to use the fallback for the input/textarea context menu to use the same as web.

[aiday-mar]

Hi everyone. This morning I have been investigating how the copy/paste code works in the editor land. I constructed a diagram to better see the dependencies. I am trying to see how I can remove the execCommand('copy'), execCommand('paste') and execCommand('cut') instances. From my initial investigation, it seems that we rely heavily on the CliboardEvent and the DataTransfer field within it to store data and pass it around, hence why we artificially trigger copy/pasting/cutting.

update : after investigating some more, I suppose the fix in the editor land, would be to write all the date which we normally store in the clipboardEvent into the clipboardService, which would include the text, html, metadata there. The issue I see is that some of the clipboardEvent data we use is computed behind the scenes, like the field files, so we would have to compute it ourselves. This field however is defined only when the user does a drag operation from what I understood, so I am wondering if we need to separate the standard copy/paste logic and the drag logic. I am trying to find a use case where files is not empty to better understand the code.