[Bluetooth] Control over page reload hack

[microbit-matt-hillsdon]

There's a page reload workaround in chooseDevice that's a real hack.

microbit-connection/lib/bluetooth.ts

Line 336 in c01107d

window.location.reload();

Ideally we'd determine if still necessary and make it an option the calling code has to be aware of.

[microbit-matt-hillsdon]

This surprised us today using Bluetooth in a prototype where the Bluetooth dialog is the first interaction with the micro:bit so you might open the dialog and then need to go look for the device / power it but instead the page reloads before you do that. We should bottom out whether this is still needed before a 1.0 (which I hope we do soon).