Update 2.0 branch to use examples namespace when creating tables.

[jmark99]

The accumulo-examples repo was updated so that table names created during eecution would be less likely to collide with any existing table names that could exist on a users system. This was done by making use of an examples namespace when creating tables.

This update has only been applied to the main branch. The same updates should be applied to the example code and documentation for the 2.0 branch.