Feature request: Set document language with parameter for changeLanguageMode command

[Livven]

It would be useful if you could optionally pass a parameter to the workbench.action.editor.changeLanguageMode command to directly set the desired language instead of opening the language list.

See also the following questions regarding this issue:

• http://stackoverflow.com/questions/40200788/how-to-change-language-mode-of-vscode-programmatically
• http://stackoverflow.com/questions/41639887/how-can-i-create-a-custom-keybinding-to-change-syntax-highlighting-to-a-specific
• https://social.msdn.microsoft.com/Forums/vstudio/en-US/25fd8d95-9de3-4465-8c64-82d68dcd2e47/shortcut-how-to-switch-between-typescript-and-html-with-one-or-two-shortcuts

And this comment: #8729 (comment)

Ideally you would also be able to set a specific language with a keyboard shortcut, though I'm not sure if passing command parameters is possible in keybindings.json. If not that would be another issue I guess.

[jrieken]

closing this as dupe of #1800. Tho it talks about a command this will be an API call like document.languageId = 'foolang'