Add a CL wrapper around the mktemp command to generate temp files on the fly for a regular IBMi job

[richardschoen]

Make life easier when needing to create a temp file from an IBM i CL/RPG job.

[richardschoen]

Create a temporary file

temp_file=$(mktemp)

Create a temporary file with a specific template

temp_file_with_template=$(mktemp /tmp/mytemp.XXXXXX)

Create a temporary directory

temp_dir=$(mktemp -d)