File Names - Source/Destination/Client/Server

Looking into the ECS documentation there is `file.name`, however
I would like to discuss and propose adding or documenting an additional file schema for `source` and `destination` (and or `client`/`server` where applicable).

This is especially useful in endpoint data and network transfers / file shares.

### Moving or Copying File
##### scenario:
`Renaming "payroll.docx" to "nothing_to_see_here.txt"`
##### example:
```

"source.file.name": "payroll.docx",
"destination.file.name": "nothing_to_see_here.txt"
```