remove ELECTRIC_CURRENT_AMPERE device class declaration from Ah unit …

[randyoo]

…registers

Since "Ah" is a unit of charge, not current, it's not appropriate to use the "current" device class.

This is to address the issue #86 that I just opened--I'm not quite sure if I got the syntax right.

[sfstar]

Thanks for opening this PR.
I understand the issue.
The amperage unit was assigned due to the lack of Ah/mAh being a valid unit of measurement.
This is indeed incorrect.

However, instead of going to unit of measurement of type none I would rather add Ah/mAh as valid units of measurement to home assistant.
Therefore, I will keep this PR open as a backup but the main attempt will focus on getting:
home-assistant/core#94730

approved for the core repository.
If this were to be declined I will go forward with changing these registers to None

[sfstar]

The discussion regarding unitofelectriccharge introduction has been stranded here: home-assistant/architecture#1052
Therefore introducing custom unit of charge in #274.
Closing this issue, since it will be resolved by the other PR.