Move enum and message formatting functions to a common/messages header where
they should be more discoverable, and also out of the util library, so they
will not be a dependency of the kernel
The are no changes in behavior and no changes to the moved code.
Blindly chose a cap of 10000 iterations for every loop, except for
the two in script_ops.cpp and scriptnum_ops.cpp which appeared to
(sometimes) be deserializing individual bytes; capped those to one
million to ensure that sometimes we try working with massive scripts.
There was also one fuzzer-controlled loop in timedata.cpp which was
already capped, so I left that alone.
git grep 'while (fuzz' should now run clean except for timedata.cpp
