Add the lastModificationTimeMs into Inode

Add the lastModificationTimeMs into Inode. Update the Inode, InodeFile, InodeFolder.
In order to see the modification time on WebUI, update the WebUI.
The Inode's lastModificationTimeMs will be set whenever the Inode's metadata changes.
@haoyuan , I followed the way how Linux filesystem does this. In Linux FS, when you just rename a file, it's LastModificationTime stays the same. Do we need to change it here?