Add Instant as type

Author: osopardo1

core/src/main/scala/io/qbeast/core/transform/LinearTransformer.scala

@@ -6,6 +6,7 @@ package io.qbeast.core.transform
 import io.qbeast.core.model.{OrderedDataType, QDataType}
 
 import java.sql.{Date, Timestamp}
+import java.time.Instant
 
 object LinearTransformer extends TransformerType {
   override def transformerSimpleName: String = "linear"
@@ -26,8 +27,9 @@ case class LinearTransformer(columnName: String, dataType: QDataType) extends Tr
       // Very special case in which we load the transformation information from JSON options
       case d: java.lang.Long if dataType.name == "IntegerDataType" => d.intValue()
       case d: java.math.BigDecimal => d.doubleValue()
-      case d: Timestamp => d.getTime()
-      case d: Date => d.getTime()
+      case d: Timestamp => d.getTime
+      case d: Date => d.getTime
+      case d: Instant => Timestamp.from(d).getTime
       case other => other
     }
   }

core/src/main/scala/io/qbeast/core/transform/Transformation.scala

@@ -4,7 +4,9 @@
 package io.qbeast.core.transform
 
 import com.fasterxml.jackson.annotation.JsonTypeInfo
-import java.sql.{Timestamp, Date}
+
+import java.sql.{Date, Timestamp}
+import java.time.Instant
 
 /**
  * Double value transformation.
@@ -56,6 +58,7 @@ case class IdentityToZeroTransformation(identityValue: Any) extends Transformati
     case v: Number if v == identityValue => 0.0
     case v: Timestamp if v == identityValue => 0.0
     case v: Date if v == identityValue => 0.0
+    case v: Instant if v == identityValue => 0.0
 
   }