ETCS signal modeling update

Description

The attribute <signalIS / isEtcsSignal> @srsVersion seems to be not used or needed. Therefore, it is suggested to deprecate it.

Further, there are other specific types of ETCS signals, which cannot be modelled currently.

tbd: details to follow

Background

Discussion about ETCS signals was initiated at railML ETCS use case working group meeting on February 26, 2021 (see [https://www.railml.org/en/event-reader/railml-is-etcs-telco-2021-02-26.html].

Links

• Forum discussion
  • Christian Rahmig, 20.02.2022: [https://www.railml.org/forum/index.php?t=msg&th=857&goto=2913&#msg_2913]
• Trac ticket
  • #459 (closed)
• Wiki documentation
  • IS:isEtcsSignal: [https://wiki3.railml.org/wiki/IS:isEtcsSignal]

Proposed solution railML 3.2

It is suggested to deprecate <signalIS / isEtcsSignal> @srsVersion.