Tables bugs 10431 and 9971

Fixes
[10431](https://trac.openmicroscopy.org.uk/ome/ticket/10431) poor error message when using an uninitialised table
[9971](https://trac.openmicroscopy.org.uk/ome/ticket/9971) silent truncation of long strings, and silently defaulting to a string width of 1.

Integration tests updated.

Read up on [9971](https://trac.openmicroscopy.org.uk/ome/ticket/9971) and decide if this is a bug fix or an API change.