Extend area_entities & area_devices to provide object not assigned to an area.

[Spamfast]

Describe the enhancement

I'd like to be able to more easily create templates that use lists of entities & devices not in any area, as discussed here. https://community.home-assistant.io/t/how-do-i-get-all-entities-not-in-any-area/1015991/3

While the solution @TheFes gave me works, it would be easier if area_entities(None) could do the same and the processing overhead would, I suspect be much lower. The same goes for area_devices.

When searching for a solution, I've found a number of other HA users looking for similar functionality.

Example usage

alias: Entity Area Check
description: ""
triggers:
  - trigger: time_pattern
    minutes: "47"
conditions:
  - condition: template
    value_template: |
      {{ 
        area_entites(none)
        |reject('search', '^device_tracker\\.(net|ble)_')
        |reject('search', '^conversation\\.')
        |reject('search', '^zone\\.home$')
        |reject('search', '^binary_sensor\\..+_noise_detect$')
        |reject('search', '^sun\\.sun$')
        |list
        |length != 0
      }}
actions:
  - action: notify.send_message
    metadata: {}
    target:
      entity_id: notify.bolg6
    data:
      message: Unassigned entities discovered.
mode: single
... 
# send me a reminder notification to assign then

Current workarounds

https://community.home-assistant.io/t/how-do-i-get-all-entities-not-in-any-area/1015991/3

Anything else?

No response