toggling breakpoints while debugger is running takes no effect

[SvenDowideit]

unless you toggle using b|B.

essentially, the 4 different places in the UI that can toggle a breakpoint need to be refactored to call the same generalised function, and the one existing function that contains the needed code is P::W::P::on_running_bp_clicked

The DB access and update code is duplicated in a number of places, so this can be simplified at the same time.

(I've started work on this)

[SvenDowideit]

fix commited.