Better Route optimistic locking

Use optimistic locking on updates or deletes where overwriting a newer state is unsafe. Resolve the current version from storage while the critical section is held.

use BetterRoute\Middleware\Write\CallbackOptimisticLockVersionResolver;
use BetterRoute\Middleware\Write\OptimisticLockMiddleware;
use BetterRoute\Middleware\Write\WpdbOptimisticLockCriticalSection;