(refactor): improve exception message (#1277)

* (refactor): improve exception message

It has been unclear that the text after a colon is a schema's name.
This PR makes this clear.

* chore(core): apply formatter

---------

Co-authored-by: Timon Back <[email protected]>

Author: AlexElin

springwolf-core/src/main/java/io/github/springwolf/core/asyncapi/components/examples/walkers/DefaultSchemaWalker.java

@@ -337,7 +337,8 @@ private Optional<Schema<?>> resolveSchemaFromRef(Schema schema, Map<String, Sche
             String schemaName = ReferenceUtil.getLastSegment(ref);
             Schema<?> resolvedSchema = definitions.get(schemaName);
             if (resolvedSchema == null) {
-                throw new ExampleGeneratingException("Missing schema during example generation: " + schemaName);
+                throw new ExampleGeneratingException(
+                        String.format("Missing schema (name = %s) during example generation", schemaName));
             }
             return Optional.of(resolvedSchema);
         }