fix: (core) Add circuit breaker pattern for database operations

Implements circuit breaker pattern to handle database failures gracefully
and prevent cascading failures. Fixes elizaOS#712.

Changes:
- Adds CircuitBreaker class with CLOSED, OPEN, and HALF-OPEN states
- Introduces BaseCircuitBreakerAdapter for database adapters
- Configurable failure thresholds and recovery timeouts
- Automatic recovery attempts in HALF-OPEN state
- Detailed logging of circuit breaker state changes

Circuit breaker configuration:
- Opens after 5 consecutive failures (configurable)
- Resets after 60 seconds in OPEN state
- Requires 3 successful operations in HALF-OPEN state to close

This helps prevent overwhelming failed database connections and provides
graceful degradation during outages.