dut_pwr: display notifcations on power failure

[hnez]

Add notification on the LCD …

… and web interface if the LXA TAC's DUT Power supply shut off due to e.g. an overcurrent or overvoltage event.

[Emantor]

Nit: maybe we should add a default handler in case none of the cases match. Otherwise looks good to me.

[hnez]

I initially agreed but I've had a second look and think we shouldn't. In the default case we would want reason to be null to make sure the Alert is set to be not visible:

tacd/web/src/TacComponents.tsx

Lines 555 to 562 in eb97382

	return (
	<Alert
	statusIconAriaLabel="Info"
	visible={reason !== null}
	action={
	<SpaceBetween size="xs">
	<MqttButton iconName="refresh" topic="/v1/dut/powered" send={"On"}>
	Turn DUT back on

This is however already the case when none of the cases match, as reason is initialized that way.

[hnez]

I've resolved merge conflicts in src/ui/screens.rs and web/src/TacComponents.tsx caused by other alert screens added to the main branch in the meantime.
Please re-approve and merge if you like.

[hnez]

Hi @KarlK90 can I get a new approval? The previous one was invalidated by required changes in a rebase.

[KarlK90]

@hnez done