Add examples to oos_util_lob.read_file and oos_util_lob.write_file

[martindsouza]

@janihur Please add @example for oos_util_lob.read_file and oos_util_lob.write_file. See other code for how to add to package body for documentation. Once you add it I will generate the docs for it.

Also be sure to do all work in the 1.1.0 branch.