Handle WebSocket close and reconnect in WebSocketProvider

[Dustin4444]

Fixes #1053

Implement WebSocket reconnection and keep-alive mechanism in WebSocketProvider.

• Add onclose, onping, and onpong event handlers to handle WebSocket close events and maintain connection.
• Utilize the #connect method for reconnection purposes.
• Add logic to re-establish subscriptions and pending requests on reconnection.
• Include a keep-alive mechanism with ping-pong to maintain the WebSocket connection.
• Modify src.ts/providers/provider-websocket.ts and lib.esm/providers/provider-websocket.js to reflect these changes.

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