refactor(cli): Use cargo metadata to detect the workspace root and target directory, closes #4632, #4928.

[FabianLars]

1. I don't know how this will influence custom runners.
2. Do we want to keep some of the old logic as a fall back? I don't really see much value in that, unless they help for 1), though we should probably fix that more explicitly then.
3. There's a TODO here, mainly because i forgot to remove that before committing, but should this function return an Error if cargo metadata fails? If not i think we should return the PathBuf directly instead of a Result.
4. Although it started as a fix for the target dir, i changed the logic for the workspace root too, should this be reverted? I can't think of a situation where cargo metadata could fail where our custom logic wouldn't.

What kind of change does this PR introduce?

• Bugfix
• Feature
• Docs
• New Binding issue #___
• Code style update
• Refactor
• Build-related changes
• Other, please describe:

Does this PR introduce a breaking change?

• Yes, and the changes were approved in issue #___
• No, hopefully.

Checklist

• When resolving issues, they are referenced in the PR's title (e.g fix: remove a typo, closes #___, #___)
• A change file is added if any packages will require a version bump due to this PR per the instructions in the readme.
• I have added a convincing reason for adding this feature, if necessary

[FabianLars]

Didn't notice that i opened it as a draft. Anywayyy not ready to merge (there is a TODO comment), but ready for review :)

[lucasfernog]

Might be a bit too crazy but if we see any issues with cargo metadata in the future, we could parse the cargo output directly with the JSON message format: https://github.com/vadimcn/vscode-lldb/blob/bc36db0bafd1b77d1cc9aa2dc9d69b221c7d4ae8/extension/cargo.ts#L137

[FabianLars]

Let's hope we won't see any issues then 😂

[FabianLars]

ah whoops, it doesn't compile yet, sorryy

[FabianLars]

So it does compile locally and the error in the workflow logs doesn't make any sense to me. Command is imported and the error is reported on a completely wrong/unrelated line

[FabianLars]

ahhh i guess it's because of the new interface/rust/desktop.rs file - Why doesn't github scream at me because of merge conflicts or something :(

[lucasfernog]

It does some magic stuff merging with dev when testing lol

[lucasfernog]

Thanks for implementing it :) this is super helpful for the mobile implementation too, since cargo-mobile sets a target in .cargo/config.

[lucasfernog]

Actually I need to make a small change in the target option to fix that :D will work on that later