[fix] JForm type number max/min limits. Fixes #3507

In case of an exception the same error message was being displayed. The JLIB_DATABASE_ERROR_ANCESTOR_NODES_LOWER_STATE message is also irrelevant most of the times, like in non-nested tables.
Changed to show actual message string from the Exception object.

Allow "zero" max/min & remove default limits

First I'd suggest not to force limits to be 0-100 when they are not defined in the element. Further we must stick to use isset() instead of !empty() for max/min because "zero" boundaries are always acceptable.

Update number.php

Update JHtmlFieldNumber-helper-dataset.php

We should not expect 'O' as value when no minimum/default value has been set for this field. *Already updated the Field class definition to allow no-limit.

Rolling back to split PRs