Print a note when `cargo new` is editing `workspace.members`

[weihanglo]

Problem

Starting from #12779, cargo new automatically adds the new package to workspace.members when invoked inside from a directory of a workspace. This is a great feature, however sometimes a bit less noticeable.

Proposed Solution

Print a notice when a workspace is found and cargo new are editing workspace.members of it. For example,

      Creating binary (application) `foo` package
+ note: adding `foo` as a workspace member of workspace `bar` at `/home/projects/bar`
  note: see more `Cargo.toml` keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

Notes

version

cargo 1.77.0-beta.1 (7bb7b5395 2024-01-20)
release: 1.77.0-beta.1
commit-hash: 7bb7b539558dc88bea44cee4168b6269bf8177b0
commit-date: 2024-01-20

[weihanglo]

cc @linyihai

This may have conflicted with #13391, or you can take this after #13391 merges :)

[linyihai]

@rustbot claim

Thank you for ping me. I'd like to addressed this after #13391

[epage]

I wonder if this could work as a status

Adding foo as member of workspace at /path

Unsure if we should use path diff for this.