feat: Implement Fallback design pattern #2846 (#3538)

* feat: implement Fallback design pattern with circuit breaker and service monitoring

* docs: add README for Fallback design pattern implementation

---------

Co-authored-by: Ilkka Seppälä <iluwatar@users.noreply.github.com>

pom.xml

@@ -252,6 +252,7 @@
     <module>backpressure</module>
     <module>actor-model</module>
     <module>rate-limiting-pattern</module>
+    <module>fallback</module>
     <module>onion-architecture</module>
   </modules>
   <repositories>