Move Discovery class into common folder (#2414)

extensions/ql-vscode/src/common/discovery.ts

@@ -1,5 +1,5 @@
 import { DisposableObject } from "../pure/disposable-object";
-import { extLogger } from "../common";
+import { extLogger } from "./logging/vscode/loggers";
 import { getErrorMessage } from "../pure/helpers-pure";
 
 /**

extensions/ql-vscode/src/query-testing/qltest-discovery.ts

@@ -1,5 +1,5 @@
 import { dirname, basename, join, normalize, relative, extname } from "path";
-import { Discovery } from "./discovery";
+import { Discovery } from "../common/discovery";
 import {
   EventEmitter,
   Event,