Remove smoothed glucose default value

This commit removes the default value for smoothed glucose properties
stored in CoreData. Since this property is optional, we don't need to
have a default value and in fact having a default value complicates
logic and requires the use of `smoothedGlucose != 0` checks.

I added a missing `smoothedGlucose != 0` as a precaution in case any
default values were persisted in CoreData.

Model/TrioCoreDataPersistentContainer.xcdatamodeld/TrioCoreDataPersistentContainer.xcdatamodel/contents

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8" standalone="yes"?>
-<model type="com.apple.IDECoreDataModeler.DataModel" documentVersion="1.0" lastSavedToolsVersion="23788.4" systemVersion="25B78" minimumToolsVersion="Automatic" sourceLanguage="Swift" usedWithSwiftData="YES" userDefinedModelVersionIdentifier="">
+<model type="com.apple.IDECoreDataModeler.DataModel" documentVersion="1.0" lastSavedToolsVersion="24512" systemVersion="25D2128" minimumToolsVersion="Automatic" sourceLanguage="Swift" usedWithSwiftData="YES" userDefinedModelVersionIdentifier="">
     <entity name="BolusStored" representedClassName="BolusStored" syncable="YES">
         <attribute name="amount" optional="YES" attributeType="Decimal" defaultValueString="0"/>
         <attribute name="isExternal" optional="YES" attributeType="Boolean" defaultValueString="NO" usesScalarValueType="YES"/>
@@ -78,7 +78,7 @@
         <attribute name="isUploadedToHealth" optional="YES" attributeType="Boolean" usesScalarValueType="YES"/>
         <attribute name="isUploadedToNS" optional="YES" attributeType="Boolean" usesScalarValueType="YES"/>
         <attribute name="isUploadedToTidepool" optional="YES" attributeType="Boolean" usesScalarValueType="YES"/>
-        <attribute name="smoothedGlucose" optional="YES" attributeType="Decimal" defaultValueString="0.0"/>
+        <attribute name="smoothedGlucose" optional="YES" attributeType="Decimal"/>
         <fetchIndex name="byDate">
             <fetchIndexElement property="date" type="Binary" order="ascending"/>
         </fetchIndex>

Trio/Sources/APS/OpenAPS/OpenAPS.swift

@@ -132,7 +132,7 @@ final class OpenAPS {
 
             return glucoseResults.map { glucose -> AlgorithmGlucose in
                 let glucoseValue: Int16
-                if shouldSmoothGlucose, !glucose.isManual, let smoothedGlucose = glucose.smoothedGlucose {
+                if shouldSmoothGlucose, !glucose.isManual, let smoothedGlucose = glucose.smoothedGlucose, smoothedGlucose != 0 {
                     glucoseValue = smoothedGlucose.rounding(accordingToBehavior: roundingBehavior).int16Value
                 } else {
                     glucoseValue = glucose.glucose