allow leading symbols _[\]^` in query param regex because they were allowed earlier

Author: nicky1038

src/schema-routes/schema-routes.ts

@@ -95,8 +95,9 @@ export class SchemaRoutes {
       this.config.hooks.onPreBuildRoutePath(originalRouteName) ||
       originalRouteName;
 
+    // TODO forbid leading symbols [\]^` in a major release (allowed yet for backwards compatibility)
     const pathParamMatches = (routeName || "").match(
-      /({[a-zA-Z]([-_.]*[a-zA-Z0-9])*})|(:[a-zA-Z]([-_.]*[a-zA-Z0-9])*:?)/g,
+      /({[a-zA-Z_[\\\]^`]([-_.]*[a-zA-Z0-9])*})|(:[a-zA-Z_[\\\]^`]([-_.]*[a-zA-Z0-9])*:?)/g,
     );
 
     // used in case when path parameters is not declared in requestInfo.parameters ("in": "path")