Expose current direction properly on state machine

[balloob]

Description:

There was a bug in prop_to_attr mapping, causing fan entity to expose self.direction instead of self.current_direction to the state machine. This was also incorrectly implemented in the demo.

I thought about just changing it all to self.direction, but that would be a breaking change, and now it is like documented 👍

This fixes it.

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 the code does not interact with devices:

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

[andrewsayre]

It looks like this line would need to change to use current_direction? Weird it passedin python 3.7?

Edit: So not the test that's the issue, but the fan platform of template is defining self.direction instead of self.current_direction. I've scanned the code base and this was the only other instance I found.

[balloob]

it didn't pass in 3.7 but there is something else odd going on there. Opened #26311 to track it.