fix: Add description field to scheme response

Author: jwilkinson87

src/main/kotlin/com/ctrlhub/core/governance/schemes/response/Scheme.kt

@@ -18,6 +18,7 @@ class Scheme @JsonCreator constructor(
     @Id(StringIdHandler::class) var id: String = "",
     @JsonProperty("name") var name: String = "",
     @JsonProperty("code") var code: String = "",
+    @JsonProperty("description") var description: String? = null,
     @JsonProperty("start_date") var startDate: LocalDate? = null,
     @JsonProperty("end_date") var endDate: LocalDate? = null,
 
@@ -33,6 +34,7 @@ class Scheme @JsonCreator constructor(
     constructor(): this(
         id = "",
         name = "",
+        description = null,
         code = "",
         startDate = null,
         endDate = null,