GATT client: support long reads

[darkyen]

In my current setup I have a MKR 1010 acting as master, which is current reading from an iPad acting as a peripheral. On the apple side, the CBPeripheralDelegate expects the Central to read data in multiple attempts with different offsets for chunking, as of now I don't see a way to override the offset in the library. I would expect this to either be abstracted, or allow readValue to expose an offset.

[sandeepmistry]

Hi @darkyen,

Thanks for providing the details, I've updated the issue title accordingly. I've marked this as an enhancement.

My preference would be the first option, for the library to handle long reads transparently.

cc/ @gvarisco