Remove last_update to save on database space

[InTheDaylight14]

sensor.playlist_sensor fills up the HA database due to the last_update attribute changing every minute. The list of playlists does not change very frequently so this feels unnecessary to pepper the database with the info.

Alternatives, the update frequency could be lowered for the playlist sensor. Say hourly updates. Or the last_update attribute could be made optional via the config flow options. I'm happy to write the PR for these if one solution is preferred.

[fcusson]

@InTheDaylight14.

Really good idea, but in case this is used by someone else I would add the requirement that this is a none breaking change.

We should implement a setting instead to blacklist certain components instead of just removing access to some information.

I think we could add in setting something like

blacklisted_attributes:
  - sensor.last_update

As for your other improvement, we could check for the frequency of the update but as always, I really want to keep the behavior of the integration as stable as possible. Same thing, I would make the update frequency controllable by the user but with a default value in absence of the setting.

I have some times after work during the week I could draft some elements and push them to your fork.