Fix entity IDs missing serial number prefix on new installations

[Poshy163]

Fixes #233

• New integrations set up via the config flow were
  generating entity IDs without the inverter serial
  number (e.g. button.15_minute_charge instead of
  button.al7011023030271_15_minute_charge). This made it
  difficult to identify which device a sensor belongs
  to, especially in multi-inverter setups.

• Adds suggested_object_id to all entity classes so HA
  includes the serial prefix in the entity ID at
  creation time, without changing the friendly display
  name. all existing installs can recreate entity ID's to the new schema

[Genesis1969]

Sensors renamed now to sensor.[SERIAL]_name_name
Devices are seperated by serialnumber, then sensorname what is right.

Looks ok to me now.

Tnx.

[Poshy163]

@CharlesGillanders bump