Add entry in the Alerts section for "No stations found in network 0x*" messages from LTN

[ThenTech]

Is your feature request related to a problem? Please describe.

LTN notifies the user when a request could not be fulfilled, because there were no stations found in the network. This type of message is currently not logged by LTN Manager.

Describe the solution you'd like

When such an event occurs, add an entry in the Alerts section with something like:

Time	ID	Route	Alert
xx:xx:xx	xx	? -> requesting station	No provider [items requested]

(Of course if there is a binding to get these alerts from LTN in the first place)

P.S. Haven't encountered any actual issues so far, usability seems good and the general layout looks great. So good job.