feat : Broadcast Signal

**Is your feature request related to a problem? Please describe.**
I would like to build a chat app in bluetooth but its seems I can't broadcast a signal that can be identified by the same app on other phones
**Describe the solution you'd like**
Two method one to broadcast a signal and and other to receive a broadcast signal with a callback as parameter (or event) the callback will need to identify the correct signal and this would need to be build by the developper
im not a expert but I think those two won't be possible in web so iam only expecting this in iOS and Android

**Describe alternatives you've considered**
I've search the documentation of every other plugin and it doesn't seems to be possible , im alone to build this app so cant build it in Java and Swift to access this feature in a native way

**Additional context**
no additional context

The issue names no files or tests; start by reviewing the plugin's existing Android and iOS Bluetooth entry points and how platform-specific APIs are exposed. Define the broadcast and receive behavior, including callback identification, and confirm that the feature works on both mobile platforms without requiring web support.

Written by the indexing model from the issue text.