feat(test): Miscellaneous improvements to test_tasks.js (#6615)

* feat(tests): Make runTestBlock able to run any gulp task

  Modify runTestBlock so that it can run any async task, not just
  ones that return a Promise, by using the async-done package
  (part of Gulp, and already an indirect dependency) to detect
  task completion.

  Celebrate by renaming it to runTestTask.

* refactor(tests): Create Tester class to encapsulate test infrastructure

  - Create Tester class to encapsulate the runTestTask,
    and reportTestResult and runAll functions.

  - Remove the unnecessary id parameter from runTestTask (code was
    already using the .name of the task function object).

  - Remove --silent flag from npm scripts so as not to suppress
    syntax error in gulpfiles.

* refactor(tests): Invoke buildAdvancedCompilationTest task directly

  Have the test task invoke the buildAdvancedCompilationTest
  (via onlyBuildAdvancedCompilationTest, to skip already-run
  prerequisites) directly, rather than by running npm.

Author: cpcallen

gulpfile.js

@@ -52,9 +52,6 @@ module.exports = {
   buildAdvancedCompilationTest: buildTasks.buildAdvancedCompilationTest,
   gitCreateRC: gitTasks.createRC,
   docs: docsTasks.docs,
-  
-  // Targets intended only for invocation by scripts; may omit prerequisites.
-  onlyBuildAdvancedCompilationTest: buildTasks.onlyBuildAdvancedCompilationTest,
 
   // Legacy targets, to be deleted.
   recompile: releaseTasks.recompile,

package-lock.json

@@ -42,7 +42,6 @@
     "lint:fix": "eslint . --fix",
     "langfiles": "gulp langfiles",
     "minify": "gulp minify",
-    "only:compile:advanced": "gulp onlyBuildAdvancedCompilationTest --debug",
     "package": "gulp package",
     "postinstall": "patch-package",
     "prepare": "gulp prepare",
@@ -53,8 +52,8 @@
     "release": "gulp gitCreateRC",
     "start": "concurrently -n tsc,server \"tsc --watch --preserveWatchOutput --outDir 'build/src' --declarationDir 'build/declarations'\" \"http-server ./ -s -o /tests/playground.html -c-1\"",
     "tsc": "gulp tsc",
-    "test": "gulp --silent test",
-    "test:generators": "gulp --silent testGenerators",
+    "test": "gulp test",
+    "test:generators": "gulp testGenerators",
     "test:mocha:interactive": "http-server ./ -o /tests/mocha/index.html -c-1",
     "test:compile:advanced": "gulp buildAdvancedCompilationTest --debug",
     "updateGithubPages": "npm ci && gulp gitUpdateGithubPages"
@@ -78,6 +77,7 @@
     "@microsoft/api-extractor": "^7.29.5",
     "@typescript-eslint/eslint-plugin": "^5.33.1",
     "@wdio/selenium-standalone-service": "^7.10.1",
+    "async-done": "^2.0.0",
     "chai": "^4.2.0",
     "clang-format": "^1.6.0",
     "closure-calculate-chunks": "^3.0.2",