Connect devices that support ANCS

[gaogaogoo]

I use this project to connect a device that supports ANCS service, iOS will require the device to be paired with the system.

1. The paired device will remain connected to the system even if the APP is closed. When the app is reopened, the device cannot be searched.
2. Some users will first connect and pair with the device in the Bluetooth list of system settings. The device cannot be searched when the app is opened.

I wish for the btleplug library to provide a list of BLE devices that are already connected to the system, and to interface with the CBCentralManager.retrieveConnectedPeripheralsWithServices function in iOS through Rust code.

Thank you!