feat: Added Microservices UI Client side composition #2698 (#3062)

* Added Microservices client side ui composition to the repo.
Added ClientSideCompositionTest, ApiGateway, ClientSideIntegrator, FrontendComponent, CartFrontend, ProductFrontend, updated pom.xml, ReadME.md.

* Improved some checkstyle changes.

* Added Random variable to re-use the random instead of creating it everytime in FrontendComponent.

* changed the Pom.xml and upadted the ReadME.md

* Changes in the README.md File as per requirement, name of the file changed from ReadME.md to README.md

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