Fix missing imports for schemaMapping in API interfaces

Author: SubhamAshok

modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java

@@ -4623,6 +4623,9 @@ public CodegenOperation fromOperation(String path,
                         !languageSpecificPrimitives.contains(r.baseType)) {
                     imports.add(r.baseType);
                 }
+                if (importMapping.containsKey(r.dataType)) {
+                    imports.add(r.dataType);
+                }
 
                 if ("set".equals(r.containerType) && typeMapping.containsKey(r.containerType)) {
                     op.uniqueItems = true;
@@ -5464,6 +5467,9 @@ public CodegenParameter fromParameter(Parameter parameter, Set<String> imports)
         if (codegenProperty.complexType != null) {
             imports.add(codegenProperty.complexType);
         }
+        if (importMapping.containsKey(codegenParameter.dataType)) {
+            imports.add(codegenParameter.dataType);
+        }
 
         codegenParameter.pattern = toRegularExpression(parameterSchema.getPattern());