feat: expose predicate to check symbolic link

Author: Hweinstock

runtimes/server-interface/workspace.ts

@@ -4,6 +4,7 @@ import { TextDocument, WorkspaceFolder } from '../protocol'
 interface Dirent {
     isFile(): boolean
     isDirectory(): boolean
+    isSymbolicLink(): boolean
     name: string
     parentPath: string
 }