expose memoryCacheContainsKey method from cache_store

[vinicius0026]

:sparkles: What kind of change does this PR introduce?

Feature

:arrow_heading_down: What is the current behavior?

No way of knowing if a key is in the memory cache.

:new: What is the new behavior (if this is a feature change)?

New method to know if a given key is present in the memory cache

:boom: Does this PR introduce a breaking change?

No

:bug: Recommendations for testing

Unit tests were added - there's not much to test really, it's a really simple new method.

:memo: Links to relevant issues/docs

:thinking: Checklist before submitting

• [x] All projects build
• [x] Follows style guide lines (code style guide)
• [ ] Relevant documentation was updated
• [x] Rebased onto current develop