Suggestion: Rename --all to --workspace

[behnam]

In rust-lang/cargo#6977, cargo's main subcommands, including check, build, and test, were updated to use --workspace instead of --all, to prevent the confusion about what the phrase "all" refers to.

Looks like cargo fmt still uses --all and have not switched to --workspace. Suggesting making that transition here, as well.

What do you think?

[calebcartwright]

Thanks for reaching out @behnam

The --all flag means something different in the cargo fmt context, more info here, and this is also a duplicate of #3911 so I'm going to close.