OTel: track workspace metadata

[zhichli]

For all events, but especially code editing/acceptance/survival events:

• file path(s)
• git head sha
• git branch
• remote repo

[vs-code-engineering]

Hi @zhichli. As a member of the team, you can help us triage this issue by referring to https://github.com/microsoft/vscode-copilot/wiki/Copilot-Inbox-Tracker and assigning an owner directly.