SVGHMI: Changes /CURRENT_PAGE_* behaviour to prevent problem whith multiclient : all clients were switching page when one was jumping.
- now PLC have to prefix page name with "!" to order page switch.
- HMI do not prefix with "!" when jumping, this avoiding looping incidently
- In case of multiple client:
CURRENT_PAGE reflects current page of last client hwo did jump
Setting CURRENT_PAGE with "!" affects all clients simultaneously

<?xml version='1.0' encoding='utf-8'?>
<BaseParams xmlns:xsd="http://www.w3.org/2001/XMLSchema" IEC_Channel="0" Name="modbus_0"/>