Feat: Language Support Status

[sambacha]

A language status item is the preferred way to present language status reports for the active text editors, such as selected linter or notifying about a configuration problem.

https://github.com/microsoft/vscode/blob/a330b89e5d83293bacee75ac910626b64ad8c3fd/src/vscode-dts/vscode.d.ts#L11839

commit: microsoft/vscode@17ed7bf
ref: microsoft/vscode#129037
more info: https://code.visualstudio.com/updates/v1_65