Move circuit breakers away from Netflix Histrix

[emmeblm]

Spring Cloud after version Hoxton.SR12 got rid of Netflix Histrix functionality.
So in order to upgrade to the latest Springboot version https://plugins.gradle.org/plugin/org.springframework.boot (which comes in the release train of spring cloud version 2021.0.x https://spring.io/projects/spring-cloud), we need to get rid of Histrix and implement the circuit breakers with a different solution.

Tasks:

• Remove Netflix Histrix dependency and implement circuit breakers in a compatible way with latest Spring Cloud release train. An option could be https://spring.io/guides/gs/cloud-circuit-breaker/
• Upgrade spring cloud and springboot dependencies