[Tech Debt] Remove FakeCacheService

[hectorgomezv]

Description

FakeCacheService was introduced to mimic the behavior of a Cache layer while running unit tests. One of its main goals was to avoid the need for having a running cache instance (Redis) while running the unit tests. This is not true anymore since the CGW does require a running Redis instance for some test suites (e.g.: redis.cache.service.spec.ts).

Moreover, there are no strict guarantees that the actual Redis behavior is mimicked by FakeCacheService, making this class a risk since bugs can be introduced unnoticed while using this class on tests.

Requirements

• Remove FakeCacheService.
• Replace FakeCacheService usages on test classes by RedisCacheService.