Fix min max states

[dnicolson]

♻️ Current situation

The this.WindowCovering.CurrentPosition values appear to be inverted, elsewhere in the code this is accounted for by a subtraction from 100. If the curtain is at 3%, setting the set_max value to 5% or 95% does not result in a closed state.

💡 Proposed solution

Adjust the logic so that the closed state sets the CurrentPosition value to 0 instead of 100.