fix nullability annotations

Author: HighKo

kotlin-atlassian-client-core-common/src/main/kotlin/com/linkedplanet/kotlinatlassianclientcore/common/api/JiraGroup.kt

@@ -23,5 +23,5 @@ import javax.validation.constraints.NotNull
 
 data class JiraGroup(
     @field:NotNull val name: String,
-    @field:NotNull val avatarUrl: String? = null,
+    val avatarUrl: String? = null,
 )

kotlin-atlassian-client-core-common/src/main/kotlin/com/linkedplanet/kotlinatlassianclientcore/common/api/JiraUser.kt

@@ -25,6 +25,6 @@ data class JiraUser(
     @field:NotNull val key: String,
     @field:NotNull val name: String,
     @field:NotNull val emailAddress: String,
-    @field:NotNull val avatarUrl: String? = null,
+    val avatarUrl: String? = null,
     @field:NotNull val displayName: String
 )

kotlin-insight-client/kotlin-insight-client-api/src/main/kotlin/com/linkedplanet/kotlininsightclient/api/model/Model.kt

@@ -233,7 +233,7 @@ sealed class InsightAttribute(
     data class Url(
         @get:JvmName("getAttributeId")
         @field:NotNull override val attributeId: InsightAttributeId,
-        val values: List<String>,
+        @field:NotNull val values: List<String>,
         override val schema: ObjectTypeSchemaAttribute?
     ) : InsightAttribute(attributeId, schema, AttributeTypeEnum.Url, true, values.joinToString(","), values){
         override fun toString() = values.joinToString(",")
@@ -242,7 +242,7 @@ sealed class InsightAttribute(
     data class Select(
         @get:JvmName("getAttributeId")
         @field:NotNull override val attributeId: InsightAttributeId,
-        val values: List<String>,
+        @field:NotNull val values: List<String>,
         override val schema: ObjectTypeSchemaAttribute?
     ) : InsightAttribute(attributeId, schema, AttributeTypeEnum.Select, true, values.joinToString(","), values){
         override fun toString() = values.joinToString(",")
@@ -337,7 +337,7 @@ sealed class InsightAttribute(
     data class Status(
         @get:JvmName("getAttributeId")
         @field:NotNull override val attributeId: InsightAttributeId,
-        @field:NotNull val status: StatusAttribute?,
+        val status: StatusAttribute?,
         override val schema: ObjectTypeSchemaAttribute?
     ) : InsightAttribute(
         attributeId,