feat: implement BatchedPollingEventSubscriber for optimized event polling.

[zy0n]

This pull request introduces a new batched event polling mechanism and integrates it into the PollingJsonRpcProvider to improve efficiency and control over event polling. The main changes include the addition of the BatchedPollingEventSubscriber class, modification of the provider to use this new subscriber, and new controls for pausing and resuming event polling.

Event polling improvements:

• Added the BatchedPollingEventSubscriber class in src/provider/batched-polling-event-subscriber.ts, which polls for events at fixed intervals instead of every block, reducing the number of eth_getLogs calls.
• Modified the _getSubscriber method in PollingJsonRpcProvider to use BatchedPollingEventSubscriber for event subscriptions, enabling interval-based polling.

Provider control enhancements:

• Added pause and resume methods to PollingJsonRpcProvider, allowing pausing and resuming of all event subscribers.

[bhflm]

lgtm :)