Fix a few broken API URLs in JS, refs D252
Fix broken pushstate routing for api explorer, refs D196
enable API explorer
add alert_subscription scope to Base.yml (for seed db data)
add AlertSubscription entity and repository interface
add route for alert_subscriptions
add scope for alert_subscriptions to koauth.php and a2.php
add alert_subscriptions scope to js login logic as well
add AlertSubscription repostiry implementation, also add DI config for this
add migration for alert_subscriptions
add alert subscriptions controller with simple get action