Add mapping for station state and error code

According to requirement modbus must return values calculated based on motor status/mode and current error code
Factor out mapping code to function and call from proper place
Implement new method to access parameters and settings

Get parameters by channel numbers and read them from ic_datae3.sdb
Get settings by string descriptions
Fix 'connection to GW lost'

- additional fix for 0z in settings
Wait for both parameters and settings to be not-0 to generate data ready event