The pattern we were using for actions required actions to be defined in
three places, an enum member containing the type string, an type
definition and a function. This combines all three of these into one by
using a helper function based on the ideas from [1].
[1]: https://phryneas.de/redux-typescript-no-discriminating-union
This is the beginning of the BLE Pybricks service implementation, so
changes are made to get a handle to the Pybricks control characteristic
and enable notifications.
Currently, only one event (the status report event) and no commands are
implemented on this characteristic.
The new status report event replaces monitoring the UART for >>>>
strings to get the current hub state.
Also includes some minor cleanup in the ble-uart/actions for consistency.
David Lechner