[lldb] Improve formatting of dlopen error messages (NFC)

Ensure there's a space between "utility" and "function", and also makes
it easier to grep/search for "utility function".

While making this change, I also re-formatted the other dlopen error messages
(with clang-format). This fix other instances of spaces missing between words,
and makes each of these strings fit a single line, making them greppable.

Differential Revision: https://reviews.llvm.org/D126078