Make broadlink switch restore its state

[akloeckner]

Breaking Change:

This could break behavior for people relying on the switch to always start up in off state.

Description:

Especially if we have a "toggle" switch (with same on/off commands), it is very useful to restore the state in home assistant. We can then guess the current state and actually switch the device on or off. This should also work after a HA restart. Which it didn't so far...

I copied the method to do so from pilight switch to broadlink switch.

Related issue (if applicable): none.

Pull request with documentation for home-assistant.io (if applicable): none

Example entry for configuration.yaml (if applicable):

switch:
- platform: broadlink
  host: !secret rmmini_host
  mac:  !secret rmmini_mac
  switches:
    receiver:
      friendly_name: "Receiver an/aus"
      command_on:    'JgBgAAABKJIVERQRFRAVNRU0FjQVEBY0FRAVEBYQFRAWEBUQFRAVERU0FhAVNBU1FDUWEBQRFDUVERU0FhAVEBURFDUUNhQRFAAFpAABKUcVAAw===='
      command_off:   'JgBgAAABKJIVERQRFRAVNRU0FjQVEBY0FRAVEBYQFRAWEBUQFRAVERU0FhAVNBU1FDUWEBQRFDUVERU0FhAVEBURFDUUNhQRFAAFpAABKUcVAAw===='

Checklist:

• The code change is tested and works locally.
• Local tests pass with tox. Your PR cannot be merged unless tests pass
• There is no commented out code in this PR.
• I have followed the development checklist

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

• Documentation added/updated in home-assistant.io

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

• The manifest file has all fields filled out correctly. Update and include derived files by running python3 -m script.hassfest.
• New or updated dependencies have been added to requirements_all.txt by running python3 -m script.gen_requirements_all.
• Untested files have been added to .coveragerc.

If the code does not interact with devices:

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

[ghost]

Hey there @Danielhiversen, mind taking a look at this pull request as its been labeled with a integration (broadlink) you are listed as a codeowner for? Thanks!

This is a automatic comment generated by codeowners-mention to help ensure issues and pull requests are seen by the right people.