OPC-UA: Update CTN "ChangesToSave" status when variable selection change.

- fixes changes not being saved when no other changes happening to configuration
- added CTNMarkModified to ConfigTreeNode in order to generalize

[main]
host = https://www.transifex.com

[beremiz-ide.beremiz]
file_filter = Beremiz_<lang>.po
minimum_perc = 0
source_file = messages.pot
source_lang = en
type = PO