Show the linked device as OneChat on the phone

The daemon sets the device properties of the library once before any
client exists, because they are global values of the library. The
properties have the OS name OneChat and the desktop platform type.
Without a known platform type, the phone ignores the name and shows the
device as "Other device".

The display name of the phone code pairing stays "Chrome (Linux)": the
server accepts only the form "Browser (OS)" with a common browser and
OS, and refuses the pairing otherwise. A comment says so.

The name applies at the pairing, so an existing link keeps its old name
until the user unlinks and pairs again.