SVGHMI: HMI is not speculating on PLC variable update anymore when sending new variable value.

HMI variable cache in JS was changed in advance for more responsive behaviour when updating a HMI tree variable. This was leading to display value different from hmi tree variable in case the expected update did not happen because PLC program did revert it.

[TOPOLOGY]
NetName=None
Nodes=0x01
Node2Present=0x01
Node2Name=SlaveNode
Node2DCFName=Slave_0_0.eds
EDSBaseName=eds