fix(afc): make walk tolerant to untraversable directories - #292

 npm run test:afc

  > appium-ios-remotexpc@5.14.3 test:afc
  > node --enable-source-maps --test --test-timeout=60000 "build/test/integration/afc.spec.js"

  ▶ AFC Service
    ✔ should list root directory and contain standard folders (133.59775ms)
    ✔ should write, read, rename and delete a file in Downloads (589.9565ms)
    ✔ should read and write files using streams (457.315375ms)
    ✔ should push and pull files between local and device (511.1235ms)
    ✖ should walk directories and include expected entries (10863.679292ms)
    ✔ should recursively pull directory with files (1755.675833ms)
    ✔ should respect overwrite option when pulling files (2186.041083ms)
    ✔ should not create empty directories when pulling with match pattern (2258.3675ms)
  ✖ AFC Service (18771.606667ms)
  ℹ tests 8
  ℹ suites 1
  ℹ pass 7
  ℹ fail 1
  ℹ cancelled 0
  ℹ skipped 0
  ℹ todo 0
  ℹ duration_ms 19277.089709

  ✖ failing tests:

  test at test/integration/afc.spec.ts:128:3
  ✖ should walk directories and include expected entries (10863.679292ms)
    Error: AFC operation READ_DIR failed with PERM_DENIED (10)
        at AfcService._doOperation (/Users/navinchandra/Documents/Projects/remote_xpc_project/appium-ios-remotexpc/src/services/ios/afc/index.ts:803:13)
        at process.processTicksAndRejections (node:internal/process/task_queues:105:5)
        at async AfcService.listdir (/Users/navinchandra/Documents/Projects/remote_xpc_project/appium-ios-remotexpc/src/services/ios/afc/index.ts:125:18)
        at async AfcService.walk (/Users/navinchandra/Documents/Projects/remote_xpc_project/appium-ios-remotexpc/src/services/ios/afc/index.ts:484:21)
        at async AfcService.walk (/Users/navinchandra/Documents/Projects/remote_xpc_project/appium-ios-remotexpc/src/services/ios/afc/index.ts:497:20)
        at async AfcService.walk (/Users/navinchandra/Documents/Projects/remote_xpc_project/appium-ios-remotexpc/src/services/ios/afc/index.ts:497:20)
        at async TestContext.<anonymous> (/Users/navinchandra/Documents/Projects/remote_xpc_project/appium-ios-remotexpc/test/integration/afc.spec.ts:130:22)
        at async Test.run (node:internal/test_runner/test:980:9)
        at async Suite.processPendingSubtests (node:internal/test_runner/test:677:7)