fix: handle null field types in parameters parser and refine macro circular dependency detection logic

Author: Illia Aihistov

lib/src/utils/docs_parser/parsers/parameters_parser.dart

@@ -52,7 +52,7 @@ class ParametersParser {
         if (variableName.startsWith('_')) continue;
 
         final name = ParserUtils.camelCaseToSnakeCase(variableName);
-        var type = member.fields.type.toString();
+        var type = member.fields.type?.toString() ?? 'dynamic';
         type = type.replaceAllMapped(ParserRegexes.wordRegex, (match) {
           final word = match.group(0)!;
           return customTypes[word] ?? word;

lib/src/utils/docs_parser/utils/parser_utils.dart

@@ -88,12 +88,12 @@ class ParserUtils {
 
         if (newExpanded == expanded) break;
 
-        if (i == _maxMacroDepth - 1) {
+        expanded = newExpanded;
+
+        if (i == _maxMacroDepth - 1 && expanded.contains('{@macro')) {
           throw 'Circular macro dependency detected or macro expansion depth '
               'exceeded the limit of $_maxMacroDepth';
         }
-
-        expanded = newExpanded;
       }
     }