remove brittle string replacing and retrieve value type from parser

src/Facility.LanguageServer/FsdDefinitionUtility.cs

@@ -41,7 +41,7 @@ public static IEnumerable<ServicePart> GetReferencedServicePartsAtPosition(this
 				.Select(field =>
 				{
 					var part = field.GetPart(ServicePartKind.TypeName);
-					var typeName = GetFieldTypeName(field);
+					var typeName = service.GetFieldTypeName(field);
 
 					return (part, typeName);
 				})
@@ -53,7 +53,7 @@ public static IEnumerable<ServicePart> GetReferencedServicePartsAtPosition(this
 				.Select(field =>
 				{
 					var part = field.GetPart(ServicePartKind.TypeName);
-					var typeName = GetFieldTypeName(field);
+					var typeName = service.GetFieldTypeName(field);
 
 					var type = service.GetFieldType(field);
 					var memberTypeName = type?.GetMemberTypeName();
@@ -84,14 +84,10 @@ private static string GetMemberTypeName(this ServiceTypeInfo type)
 			return null;
 		}
 
-		private static string GetFieldTypeName(this ServiceFieldInfo field)
+		private static string GetFieldTypeName(this ServiceInfo service, ServiceFieldInfo field)
 		{
-			return field.TypeName
-				.Replace("[]", "", StringComparison.Ordinal)
-				.Replace("map<", "", StringComparison.Ordinal)
-				.Replace("nullable<", "", StringComparison.Ordinal)
-				.Replace("result<", "", StringComparison.Ordinal)
-				.Replace(">", "", StringComparison.Ordinal);
+			var type = service.GetFieldType(field);
+			return type?.ValueType?.ToString() ?? type?.ToString() ?? field.TypeName;
 		}
 	}
 }