Add metadata to HUT_CUSTOM_CB Opts

[okeuday]

Without the metadata present, it is impossible to get the file/line/mfa
preprocessor info, unless Opts is used explicitly.

[tolbrino]

Thanks. I suspect it could make sense to add the metadata to the log/5 clause as well, merging it with whatever is given as opts, such that there is a common minimum set of opts for all clauses.