[vscode] support proposed API scmHistoryProvider introduced with vscode 1.83

[rschnekenbu]

A new proposed API has been introduced in vscode 1.83 and is used by the git builtin extension: vscode.proposed.scmHistoryProvider.d.ts.

[rschnekenbu]

This proposed API only adds an additional optional Property on top of SourceControl and some new types only used by this proposed API. So we can close this task as is.