Change default value of "Show description (if present)" preference #134

(thanks again for the time and effort put into this extension - it's a real productivity improvement for database testing using Oracle SQL Developer)

Following on from this discussion in the utPLSQL slack channel;

The 1.3.1 release makes the tree-table view of tests the default (the use of this view being controlled via the “Show suites (hierarchical view of tests)" preference). In the tree table view, an improvement would be to see the descriptions associated with tests and context's if these are present. This can be controlled by the preference "Show description (if present)", but the default of this preference is "disabled".

This enhancement request, is to change the default value of the preference "Show description (if present)" to be "enabled".

Also, in the context of the introduction of the tree-table view, it's worth considering whether the other preference defaults are still sensible - though these aren't the subject of this enhancement request.