Post to EMONCMS & Updated Endian for storage values

[herbi3]

1. added class StorageInverter(SolarEdge) to read these, set solaredge_modbus.StorageInverter(parent=master).read_all() with master set as master = solaredge_modbus.Inverter(host=LEADER_HOST, port=LEADER_PORT, retries=10, timeout=10, unit=1)

This new class has self.wordorder = Endian.Little instead of self.wordorder = Endian.Big - now the values are human readable for:

• "export_control_mode"
• "export_control_limit_mode"
• "export_control_site_limit"
• "storage_control_mode"
• "storage_ac_charge_policy"
• "storage_ac_charge_limit"
• "storage_backup_reserved_setting"
• "storage_default_mode"
• "rc_cmd_timeout"
• "rc_cmd_mode"
• "rc_charge_limit"
• "rc_discharge_limit"

2. Added asynchronous and configurable script for posting data into EMONCMS. Emoncms then posts into its own MQTT, then telegraph gets this data and posts it to Influx. Why not just go straight to influx? because in EMONCMS it allows for post-processing of the data before sending the final values to influxdb & it provides an API for reading the live data.

this script is configurable, where simply change enable=0 to enable=1 for each item attached to the inverter, and it will do its best to read all values at the same time. it will also calculate the Consumption, Import, Export, Solar, Batteries, Grid etc. all in the one go.