Allow set a custom order for domain tables

[fpuga]

Now, when domain values are read from database those values are 'alphabetically' sort based on the database collation. In some situations a custom order is need, for example when a special value like '-All-' wants to be included in the combo.

A possible implementation:
Add a new tag to the domainreader element
database_column_name

When this clause is present do the order by using that column.