Focus on the terminal when running a command

For command line apps in particular, it would often be handy for the focus to move to the vscode terminal when running them. This seems like it's the responsibility of the extension to do rather than a setting on the terminal extension.

• This should likely be the default behavior
• This should probably have a setting to disable this behavior.
• It's possible that it makes sense to have different categories of runnables have different behavior (e.g. cargo run, cargo test, cargo check)

I didn't find a matching existing issue when searching, but it's probable that one has been raised before on this, so I'd not be surprised if this is a dupe.

No file or test is named. Start by locating the extension's runnable command entry points and its VS Code terminal integration, using cargo run, cargo test, and cargo check as the behavior categories described in the issue. Clarify the default focus behavior, opt-out setting, and whether categories need separate handling before implementation.