Workflow visualization with Temporal’s Timeline View

Introduced a new 'Timeline' view to the Temporal Web UI for visualizing workflow execution. This view represents the flow of Events over time, using 'Event Groups' to consolidate related events (e.g., ActivityTaskScheduled, Started, Completed) into single rows spanning their duration. It supports zooming, scrolling, filtering by event type, and displays outcome colors and retry information. The implementation utilizes the 'vis-timeline' open-source library with Svelte.