Log the name of the dependency that changed

[torhovland]

Fixes #13859 by adding the name of the dependency to the "dependency info changed" log message.

There is a surprising test output after this. See code review.

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[torhovland]

This message looks strange to me. Should it not output registry rather than registry_shared here?

[epage]

Part of the problem is we only report the first dependency, rather than all.

I suspect what is happening here is we are reusing registry_shared with a version from a couple builds back. This is a different hash than the immediately prior build, so it requires rebuilding bar but this isn't quite clear without more context.

I wonder if this change will cause more confusion than good and we should defer to #2904 which would add a cargo report subcommand for reporting why the last command rebuilt and we can include a lot more context.

[weihanglo]

See #13859 (comment), yet it might need some design discussions before proceed.