Template binary sensor to not track all state changes

[amelchio]

Breaking change:

Template binary sensors for which we could not determine what states to track to re-render will now only be updated when manually refreshed using the homeassistant.update_entity service.

Description:

More or less a copy+paste of #17276 and #17319, but for binary_sensor. I did have to introduce async_update() to enable forced updates.

Also updates the tests with async/await syntax.

Related issue (if applicable): home-assistant/architecture#85

Pull request in home-assistant.io with documentation (if applicable): home-assistant/home-assistant.io#<home-assistant.io PR number goes here>

Example entry for configuration.yaml (if applicable):

binary_sensor:
  platform: template
  sensors:
    static:
      value_template: '{{ "true" }}'

Checklist:

• The code change is tested and works locally.
• Local tests pass with tox.
• There is no commented out code in this PR.

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated in home-assistant.io

If the code does not interact with devices:

• Tests have been added to verify that the new code works.

[amelchio]

Added breaking change label (and note).