Unable to investigate whether GraphQL Client had a Cache HIT or MISS, missing logging

### Expected Behaviour
DEBUG logging is available when there is a Cache HIT or MISS in executing GraphQL Queries

### Actual Behaviour
DEBUG logging is not available when there is a Cache HIT or MISS in executing GraphQL Queries. It is thus not possible, especially on AEM 6.5 to investigate / debug issues with GraphQL Client Cache configurations / functionality.

### Reproduce Scenario (including but not limited to)
Especially reproducable on AEM 6.5 as on AEM Cloud Service, there are other tools available for this.

#### Steps to Reproduce
1. Configure GraphQL Client Cache configuration that is incorrect
2. Use GraphQL Client on any CIF Core Components and notice the functionality is working, but not picking up from the cache

#### Platform and Version
AEM 6.5

#### Sample Code that illustrates the problem

#### Logs taken while reproducing problem

Start by locating the GraphQL Client cache execution path and any existing DEBUG logging. Reproduce the incorrect cache configuration on AEM 6.5 and inspect the resulting behavior. Done means DEBUG output clearly identifies whether each query was a cache HIT or MISS.

Written by the indexing model from the issue text.