We need to be able to handle floating point numbers right on the
boundary between two icons. This means our from..to configurations must
perfectly align at each end, and the algorithm to select those must not
be both less-than-or-equal (<=) AND more-than-or-equal (>=).
After this change:
>>> get_icon_between(icon_states["battery_charge_level"], 0)
'battery-alert-variant-outline'
>>> get_icon_between(icon_states["battery_charge_level"], 9.9)
'battery-alert-variant-outline'
>>> get_icon_between(icon_states["battery_charge_level"], 10)
'battery-10'
>>> get_icon_between(icon_states["battery_charge_level"], 39)
'battery-30'
>>> get_icon_between(icon_states["battery_charge_level"], 39.9)
'battery-30'
>>> get_icon_between(icon_states["battery_charge_level"], 39.9999)
'battery-30'
>>> get_icon_between(icon_states["battery_charge_level"], 40)
'battery-40'
>>> get_icon_between(icon_states["battery_charge_level"], 99.99)
'battery-90'
>>> get_icon_between(icon_states["battery_charge_level"], 100)
'battery'
>>> get_icon_between(icon_states["battery_charge_level"], 101)
'battery'
