RFC: Only use supported light properties

[amelchio]

Description:

Many light platforms support multiple products with differing features. This means that they can have properties that are not actually valid for the active device and will potentially fail when accessed. An example of such an issue is #15339.

This PR changes the light component so it only reads properties that are relevant for the supported features. Thus, light platforms will not have to guard each property that could be invalid.

The change could reveal some missing features like I fixed in a few tests.

I am unsure about the change to light/mqtt.py and I would like help to avoid the pylint comment.

Related issue (if applicable): fixes #

Checklist:

• The code change is tested and works locally.
• Local tests pass with tox.

If the code does not interact with devices:

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

[rytilahti]

From a quick look (w/o testing) this looks what one should be expecting already; when the platform itself already reports its supported features, it should not have to need to guard accesses to irrelevant features 👍

[balloob]

I think that this is too what I would expect.