| Links are a critical facet of REST. They provide the power to navigate to related items. It makes it possible for other parties to navigate around your API without having to rewrite things every time there is a change. Updates in the client is a common problem when the clients hard-code paths to resources. Restructuring resources can cause big upheavals in code. If links are used and the navigation route is maintained, it becomes easy and flexible to make such adjustments.

EX:
$ curl localhost:8080/api/employees/1
{
"firstName" : "Frodo",
"lastName" : "Baggins",
"description" : "ring bearer",
"_links" : {
"self" : {
"href" : "http://localhost:8080/api/employees/1"
}
}
}
-- | --

Ref: https://spring.io/guides/tutorials/react-and-spring-data-rest/

Update API CountryController.findAll() to support paging

Purpose: simplify the code logic in the Services classes