[Terminal_ Sandbox]: Do not allow reading arbitrary paths inside the $HOME folder

[dileepyavan]

Currently in sandbox mode, all the folders/files can be accessed.

Expected:

• Not to allow reading arbitrary paths from $HOME folder.
• Allow to read paths that are only needed per command thats executing in sandbox mode.

[vs-code-engineering]

Hi @dileepyavan. 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.