add timer only mode, more sane default config

esp32/include/HomieTypes.h

@@ -45,6 +45,8 @@ static const char *SENSOR_STRING[] = {
 #define MISSING_SENSOR -2
 //plant uses only cooldown and duration, moisture is measured but ignored, allowedHours is ignored (eg. make a 30min on 30min off cycle)
 #define HYDROPONIC_MODE -3
+//plant uses cooldown and duration and workhours, moisture is measured but ignored
+#define TIMER_ONLY -4
 
 typedef struct PlantSettings_t
 {

esp32/include/PlantCtrl.h

@@ -75,6 +75,12 @@ public:
         return SENSOR_STRING[mode];
     }
 
+    bool isTimerOnly()
+    {
+        long current = this->mSetting->pSensorDry->get();
+        return equalish(current, TIMER_ONLY);
+    }
+
     bool isHydroponic()
     {
         long current = this->mSetting->pSensorDry->get();
@@ -94,7 +100,7 @@ public:
      */
     bool isPumpRequired()
     {
-        if (isHydroponic())
+        if (isHydroponic() || isTimerOnly())
         {
             // hydroponic only uses timer based controll
             return true;