[Bug] Avoid two Zenoh entities to open the same serial device

[cguimaraes]

Describe the bug

Two Zenoh entities running in the same machine (e.g., a zenohd and a zenoh peer subscriber) might try to open the same serial device if it is advertised in during the scouting procedure.

As short-term solution, Zenoh must flag the serial device with exclusive usage.
Currently, Z-Serial is setting it as false.
https://github.com/ZettaScaleLabs/z-serial/blob/master/src/lib.rs#L203

As long-term solution, we should think on how to advertise serial links in the scouting procedure, since currently the locator as only local meaning.

To reproduce

1. Compile zenohd with serial support
2. Start zenohd with a serial locator
3. Start a zenoh peer subscriber

System info

• Platform: macOS
• Commit: 585af65