Make HealthChecks configurable

Summary the /server/health API endpoint serves different metrics. it would be nice to turn on/off which ones should be checked for the health-check to be OK. Basic Example _No response_ Motivation I've setup the smtp-connectiion for directus. the health-check includes opening a smtp-connection each time the health-check url is called it opens an smtp-connection to check if the connection is available. my mail-host rate-limited me because of regular health-checks every 60 seconds. so i would love to disable smtp-health-checking Detailed Design The Implementation should add a configuration-page in directus backend, or at least some configuartion variables to switch off health-checking for specific services (eg.: smtp, s3, etc) Requirements List Must Have: • A • B Should Have: • C Could Have: • D Won't Have: • E Drawbacks if the selected features are not included in health-checking, you are not aware of they're abili…