fix: Stop crashing when redis is offline and ignoreErrors on cache op…

[mesinger]

Description of change

PR #7630 introduced the ignoreErrors flag for ConnectionOptions. For me this updated did not fix my problem (also mentioned in the same PR #7630).
From my subjective opinion, typeorm should still function even though redis caching is not available. typeorm will be able to query like regular from the database overall increasing the resilience of systems using typeorm.

This fix adds an error callback for the internally used redis client, logging instead of throwing an error when ignoreErrors is set.

Pull-Request Checklist

• Code is up-to-date with the master branch
• npm run lint passes with this change
• npm run test passes with this change
• This pull request links relevant issues as Fixes #0000
• There are new or updated unit tests validating the change
• Documentation has been updated to reflect this change
• The new commits follow conventions explained in CONTRIBUTING.md

[pleerock]

Thank you for contribution! 🎉

[Juantrix123]

This PR introduces an error in RedisQueryResultCache class, since the connect method of the redis client is not called.
This causes (ClientClosedError: The client is closed) when cache is used

[mesinger]

You are right, should be fixed here #8894