cmd/go/internal/mvs: indicate the actual version when printing a mismatched ModuleError

Previously, we suppressed the module version annotation if the last
error in the stack was a *module.ModuleError, regardless of its path.
However, if the error is for a replacement module, that produces a
confusing error message: the error is attributed to the last module in
the error path, but actually originates in the replacement (which is
not otherwise indicated).

Now, we print both the original and the replacement modules when they
differ, which may add some unfortunate redundancy in the output but at
least doesn't drop the very relevant information about replacements.

Fixes #35039

Change-Id: I631a7398033602b1bd5656150a4fad4945a87ade
Reviewed-on: https://go-review.googlesource.com/c/go/+/247765


Reviewed-by: Jay Conrod <jayconrod@google.com>