Added new config options in the main settings menu for covers.
This allows you to define the total time a cover takes to go from opened to closed (or vice-versa) and allows you to set a specific opening based on that.
This basically re-implements #769 in a more streamlined way.

Option description:
Force use of virtual position: allows you to force the usage of a time-base computed position even if your cover has it in theory based on its definition
Time from opened to closed (seconds): The time it takes for the cover to go from fully closed to fully opened in seconds
Status refresh interval: The time it takes for the entity to be refreshed in HA
Device doesn't support precise positioning: Set this if your device reports a dpcode where you should be able to set a precise position but it doesn't work (typically, you try to set a specific percentage of opening and nothing happens)
Let me know on discord if this fixes the issues you might have with your covers (https://discord.gg/3EgfG5sZ4Y)
Enjoy!