support multi tabs

[LawyZheng]

:rocket:	This description was created by Ellipsis for commit adf8cc508e0f323c8b31d3998538aad4e3b45ca0

Summary:

This PR adds support for managing multiple browser tabs and video artifacts in Skyvern, enhancing BrowserState, BrowserManager, and BrowserFactory.

Key points:

• Adds support for managing multiple browser tabs and video artifacts in Skyvern.
• Enhances BrowserState with get_working_page and set_working_page methods.
• Updates BrowserManager to handle multiple video artifacts using get_video_artifacts.
• Modifies BrowserFactory to support multiple video recordings per task or workflow run.
• Replaces video_artifact_id with a list of VideoArtifact in BrowserArtifacts.
• Updates error handling and logging for page and video management.

---

Generated with :heart: by ellipsis.dev