support clean metrics of OrphanFilesCleaner

[chongchongxiao]

Purpose

Linked issue: close #114

Support clean metrics of OrphanFilesCleaner

    listDirectoriesDuration
    listDirectories
    listFileStatusDuration
    listFileStatusTasks
    listUsedFilesDuration
    usedFiles
    scanOrphanFilesDuration
    orphanFiles

Tests

No.

API and Format

No.

Documentation

No.

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