refactor(utils): reduce number of utils (#1085)

* refactor(utils): remove utils.grep

* refactor(utils): replace utils.scanDirectory w/ fast-glob

Note that fast-glob is already in our dependency graph anyway.

package.json

@@ -28,6 +28,7 @@
     "android-versions": "^1.5.0",
     "cordova-common": "^4.0.1",
     "execa": "^4.0.2",
+    "fast-glob": "^3.2.4",
     "fs-extra": "^9.0.1",
     "is-path-inside": "^3.0.2",
     "nopt": "^4.0.3",