Support scmResourceState in when clauses

fixes #86180

* Adds `contextValue?: string` to the SourceControlResourceState
* Allows when clause in scm/resourceState/context menus to use scmResourceState

src/vs/workbench/api/common/extHost.protocol.ts

@@ -715,7 +715,8 @@ export type SCMRawResource = [
 	UriComponents[] /*icons: light, dark*/,
 	string /*tooltip*/,
 	boolean /*strike through*/,
-	boolean /*faded*/
+	boolean /*faded*/,
+	string /*context value*/
 ];
 
 export type SCMRawResourceSplice = [