55e724e8d8 introduced <p> elements on
notifications. however this is undesirable on the notification action
text. This splits the Notification component into one that is pre change
and one that is post change.
Fixes #394
The Pybricks firmware now includes the BLE Device Information Service
to provide firmware and Pybricks protocol versions.
For now, checking that the service is present is enough to know that the
firmware is up to date. But we will need to add additional checks as
soon as the protocol is changed.
David Lechner