refactor(webhooks): name the webhook event type enums

The type field on each webhook family and the resourceType on the wallet
operation data types declared their enums inline. Each family's event names
are now a component schema, and WalletOperationResourceType is shared by the
completed and failed data types. The wire format is unchanged.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MYijrrgsrFLJZ5fkmC5XwJ

Author: Shreya