BREAKING: Use fully qualified names for attributes

[Meatballs1]

Resolves #72
Resolves #108
Resolves #103
Resolves #118

This is a breaing change that means manually configured MQTT configurations in HA will need updating. I don't have much experience running this with HADiscovery enabled so would be good to get some feedback if further changes are required for that.

I suspect autodiscovered items in HA will also need to be deleted for changes to come through?

To change something like SetpointTemperature in the following configuration:

number:
  - name: "Set Point Temperature"
    unique_id: "freezer_set_point_temperature"
    state_topic: "homeconnect/freezer/state"
    value_template: "{{ value_json.SetpointTemperature }}"
    command_topic: "homeconnect/freezer/set"
    command_template: "[{\"uid\":8198,\"value\": {{ value }} }]"
    min: -26
    max: -16
    icon: mdi:snowflake-thermometer
    unit_of_measurement: "°C"
    availability:
      - topic:  "homeconnect/LWT"
      - topic:  "homeconnect/freezer/LWT"
    availability_mode: all
    device:
      identifiers: "freezer"

Needs to become:

number:
  - name: "Set Point Temperature"
    unique_id: "freezer_set_point_temperature"
    state_topic: "homeconnect/freezer/state"
    value_template: "{{ value_json['Refrigeration.Common.Setting.Freezer.SetpointTemperature'] }}"
    command_topic: "homeconnect/freezer/set"
    command_template: "[{\"uid\":8198,\"value\": {{ value }} }]"
    min: -26
    max: -16
    icon: mdi:snowflake-thermometer
    unit_of_measurement: "°C"
    availability:
      - topic:  "homeconnect/LWT"
      - topic:  "homeconnect/freezer/LWT"
    availability_mode: all
    device:
      identifiers: "freezer"

Example documentation probably needs a fair amount of work after this. But should fix issues going forwards with clashing names of items.