[BugFix] Make "logging_suppress" in SystemSettings Mutable and Then Actually Suppress Logging Service

[deeleeramone]

1. Why?:

   • To provide users with a way to resolve [Bug] Getting a HTTPS error pointing to us.i.posthog.com when running the basic getting started code #6926 locally.
     • This PR provides a kill switch to completely disable the LoggingService.
   • The SystemSettings class has an attribute, logging_suppress, and it is immutably set as False.
   • Even if it was mutable, there is no reference to this setting anywhere in the code, it won't do anything.

2. What? :

   • Allows logging_suppress to be defined in system_settings.json.
   • When true, the file and PostHog handlers are not added, nothing gets recorded to the ~/OpenBBUserData/logs folder.

3. Impact:

   • Improves compatibility over VPN and blocking network infrastructure.
   • Improves user privacy by offering a complete offramp to the logging service.

4. Testing Done:

   • Add tosystem_settings.json and observe that no startup log file is created.:

{
    "logging_suppress": true
}