Resolves https://github.com/zed-industries/zed/issues/57999

This diff fixes the macOS Edit menu showing Copy and Paste as disabled
when a terminal is focused. Terminal shortcuts already worked because
keybindings dispatch `terminal::Copy` and `terminal::Paste`, but the app
menu validates `editor::Copy` and `editor::Paste`, which the terminal
view did not expose.

With this change, the terminal view handles the editor Copy and Paste
actions by delegating to the existing terminal copy and paste paths.
This keeps keyboard behavior unchanged while allowing menu validation
and menu dispatch to work correctly for focused terminals.

Release Notes:
- Fixed `Copy` and `Paste` being disabled in the macOS `Edit` menu when
a terminal is focused.

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Co-authored-by: dino <dinojoaocosta@gmail.com>