Fix the parsing of the temperature unit value (#14056)

CMCIII will yield as temperate unit '°C' (or °F), which is not
'degree C'. The ° isn’t even encoded properly, so an additional
encoding is included for good measure. Both rar and encoded
values are used for the look up.

Previously these values were stored as 'state' sensor entries,
making them sadly utterly useless.

includes/discovery/sensors/rittal-cmc-iii-sensors.inc.php

@@ -76,8 +76,10 @@ foreach ($cmc_iii_var_table as $index => $entry) {
                 $cmc_iii_sensors[$sensor_id]['multiplier'] = substr($entry['cmcIIIVarScale'], 1);
             }
 
-            $unit = $entry['cmcIIIVarUnit'];
+            // encode string to ensure that degree sign may be used properly for unit comparison
+            $unit = utf8_encode($entry['cmcIIIVarUnit']);
             $type = 'state';
+            $temperature_units = ['degree C', 'degree F', '°C', '°F'];
             if ($unit == 'mA') {
                 //In some cases we get a mA value. However, the cmcIIIVarScale is simply 1.
                 //Therefore, we must hardcode the divisor here to calculate the value into A.
@@ -92,7 +94,7 @@ foreach ($cmc_iii_var_table as $index => $entry) {
                 $type = 'power_consumed';
             } elseif ($unit == 'Hz') {
                 $type = 'frequency';
-            } elseif ($unit == 'degree C' || $unit == 'degree F') {
+            } elseif (in_array($unit, $temperature_units)) {
                 $type = 'temperature';
             } elseif ($unit == 'l/min') {
                 $type = 'waterflow';