Fire events for ISY994 control events

[OverloadUT]

Description:

A very small code change that massively increases the capability of Hass in an ISY994 household.

Before, Hass was only aware of the state change on all Insteon devices. With this change, Hass emits events every time a "Control" event happens in the Insteon network regardless of what state changes resulted from that Control.

• This can be useful, for example, to tell when a light switch is pressed "on" even though the status of that switch is already on.
• More excitingly, it allows the capture of "Fast On" and "Fast Off" events, which the user does by double-tapping the switch on or off. This is a great way for users to set up automations that occur when a double-tap happens.
• Even more excitingly this allows Insteon remotes, which are nice small remotes with up to 8 buttons, to function as buttons directly within Hass, rather than requiring them to be bound to scenes or devices and relying on their status updates.

There are also some changes here to support UNKNOWN states from ISY, which is a PyISY breaking change in the new version that this PR utilizes.

Pull request in home-assistant.github.io with documentation (if applicable): Documentation update will be needed, pending approval of the event-based approach here.

Example entry for configuration.yaml (if applicable):

automation:
  - alias: turn off living room on double tap off of switch near garage
    trigger:
      platform: event
      event_type: isy994_control
      event_data:
        entity_id: light.lr_track_lights_front_slave
        control: 'DFOF'
    action:
      service: light.turn_off
      entity_id: light.lr_track_lights_rear

Checklist:

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

• Documentation added/updated in home-assistant.github.io

If the code communicates with devices, web services, or third-party tools:

• Local tests with tox run successfully. Your PR cannot be merged unless tests pass (NO ISY994 TESTS EXIST)
• New dependencies have been added to the REQUIREMENTS variable ([example][ex-requir]). (pending PyISY version update)
• New dependencies have been added to requirements_all.txt by running script/gen_requirements_all.py. (pending PyISY version update)

[OverloadUT]

Removed the WIP tag. This PR is now ready for full review now that the PyISY library published version 1.1.0

[OverloadUT]

Closing, as everything here will be part of #10805