Add environment support to Feature services

Summary

Add environment namespaces support to feature services

• Closes #1335 (closed)

Setup

New schema:

CREATE TABLE minds.feature_toggles_cache_ns (
    environment text,
    feature_name text,
    data text,
    created_at timestamp,
    stale_at timestamp,
    PRIMARY KEY (environment, feature_name)
);

Updated CLI command:

php cli.php features sync --environment=production,canary,staging

Updated Forever runner:

php cli.php features sync --forever --environment=production,canary,staging

Steps to test

• Get pods using kubectl get pods | grep 'goal-unleash-sync-namespaces'
• SSH into php-fpm one with kubectl exec -ti goal-unleash-sync-namespaces-app-<RANDOM ID> sh
• Execute cd /var/www/Minds/engine && php cli.php features sync --environment=development,sandbox
• The above command will sync two environments. Ensure there are no Exceptions outputted
• On another terminal, get into Cassandra shell with kubectl exec -ti cassandra-0 cqlsh
• Execute expand on; SELECT * from minds.feature_toggles_cache_ns;
• Ensure there are feature flag objects listed twice (one for development, other for sandbox) and that the dates are in the range of sync operation (watch out the timezone!)
• Go to https://goal-unleash-sync-namespaces.minds.io/, log in with an administrator
• Open menu > Admin > Features
• Ensure Environment is correct and compare the GitLab columns with what's on the Enabled tab on https://gitlab.com/minds/infrastructure/feature-flags/-/feature_flags/ for the corresponding environment spec.
• You can also use https://goal-unleash-sync-namespaces.minds.io/admin/features;for=0xemi to check feature for %pro and %admin groups, per example.

Note: As the previous MR, the database check part of might be tricky for @xander-miller to test. The main concern is that critical features are turned on (media modals, etc).

Estimated Regression Scope

Everything related to feature flags.