Add Troubleshooting documentation for `dataSize` option in `open`

[alanking]

Using the open call as it exists on versions of iRODS between 4.2.9 and 4.3.0 can lead to errors in certain resource configurations. The workaround is to change the default dataSize value from -1 to 0, as seen here:

python-irodsclient/irods/manager/data_object_manager.py

Line 373 in 9c3958a

dataSize=-1,

This workaround should be documented in a Troubleshooting section in the README.

The underlying issue has been resolved in iRODS 4.3.1.

See irods/irods#7275 and irods/irods#7154 for details