Templates: fix azimuth 0 not allowed (#26997)

templates/definition/tariff/forecast-solar.yaml

@@ -16,7 +16,8 @@ params:
     help:
       en: -180 = north, -90 = east, 0 = south, 90 = west, 180 = north
       de: -180 = Norden, -90 = Osten, 0 = Süden, 90 = Westen, 180 = Norden
-    example: 180
+    type: int
+    example: 0
     required: true
   - name: horizon
     description:

util/templates/types.go

@@ -273,9 +273,9 @@ func (p *Param) IsDeprecated() bool {
 func (p *Param) IsZero(s string) bool {
 	switch p.Type {
 	case TypeInt:
-		return cast.ToInt64(s) == 0
+		return cast.ToInt64(s) == 0 && p.Name != "az"
 	case TypeFloat:
-		return cast.ToFloat64(s) == 0
+		return cast.ToFloat64(s) == 0 && p.Name != "az"
 	case TypeDuration:
 		return cast.ToDuration(s) == 0
 	default: