Allow for filtering of Bluetooth LE devices returned from bluetooth library

[kirk-quinbar]

Any function returning devices should allow for filtering to only return heart rate devices. i believe the UWP samples from Microsoft may show how to do that.

• filter on name
• filter on whether its a heart rate device

[kirk-quinbar]

name filtering has been added.

[kirk-quinbar]

filtering using gattservices to only allow heart rate devices to be returned from heartdevicewatcher has been added, but will only work on paired devices. current version of uwp bluetooth apis wont allow for querying gattservices on unpaired devices.