Revert "Revert "add 'configuration' (read uri/path) of workspace config file, #41408""

This reverts commit 1cacde3496.

src/vs/workbench/api/node/extHostExtensionService.ts

@@ -22,6 +22,7 @@ import { Barrier } from 'vs/base/common/async';
 import { ILogService } from 'vs/platform/log/common/log';
 import { IEnvironmentService } from 'vs/platform/environment/common/environment';
 import { ExtHostLogService } from 'vs/workbench/api/node/extHostLogService';
+import URI from 'vs/base/common/uri';
 
 class ExtensionMemento implements IExtensionMemento {
 
@@ -108,6 +109,7 @@ class ExtensionStoragePath {
 				join(storagePath, 'meta.json'),
 				JSON.stringify({
 					id: this._workspace.id,
+					configuration: URI.revive(this._workspace.configuration).toString(),
 					name: this._workspace.name
 				}, undefined, 2)
 			);