feat: resolve OCPP 1.6 configuration keys to OCPP 2.0 equivalents transparently

feat: resolve OCPP 1.6 configuration keys to OCPP 2.0 equivalents transparently

Add resolveKey() inside ConfigurationKeyUtils that maps OCPP 1.6 key
names to their OCPP 2.0 equivalents (MeterValuesSampledData →
TxUpdatedMeasurands, ConnectionTimeOut → EVConnectionTimeOut, etc.)
transparently in get/add/set/delete operations. Remap keba-ocpp2
template keys and add missing OCPP 2.0 variables. Add exhaustive
tests for key resolution across all OCPP versions.