Update 2.0 branch to use examples namespace when creating tables.

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.

Compare the 2.0 branch's example code and documentation with the corresponding updates on the main branch, focusing on table creation and the examples namespace. Verify that all affected examples create tables within that namespace and that the 2.0 documentation describes the same behavior.

Written by the indexing model from the issue text.