Fix: Creating relationship between otel entity and ElastiCache redis cluster

[AravindKumar8520]

Ticket -> https://new-relic.atlassian.net/browse/NR-259478

This PR is about creating candidate file for AWS_ELASTICACHE_REDIS_CLUSTER, to create the relationship between the Otel/APM and AWS_ELASTICACHE_REDIS_CLUSTER

1. For this we have created a python test app with Otel provider
2. Here is the doc link which explain the test app creation and metrics -> https://docs.google.com/document/d/1c54W-slYouCFpnjPe1cG-JGATHpTgKgkTjC4dVmKVps/edit
3. Here is the metric table -> https://staging.onenr.io/0gR7nygYxwo

Checklist

• [x] I've read the guidelines and understand the acceptance criteria.
• [x] The value of the attribute marked as identifier will be unique and valid.
• [x] I've confirmed that my entity type wasn't already defined. If it is I'm providing an explanation above.

[CLAassistant]

All committers have signed the CLA.

[javimb]

Also, I'd split relationships/synthesis/EXT-SERVICE-to-INFRA-ELASTICACHE-REDIS-CLUSTER in two and would move the rule for APM to a new relationships/synthesis/APM-APPLICATION-to-INFRA-ELASTICACHE-REDIS-CLUSTER file, so filenames are consistent with their content.

[AravindKumar8520]

By checking the regular expression we have modifed the regex regex: "^Datastore/instance/Redis/[^/].cache.amazonaws.com/[0-9]+" to "^Datastore/instance/Redis/[^/]\.cache\.amazonaws\.com/[0-9]+"

As we are unable to see the instrumented redis cluster in apm entity, this may not be the actual problem but as a best practice we have added \. after cache in the above regular expression