Allow defining the data-role for the "SYSADMIN" module.

After TEIID-1246, there is no need for granting explicit data role permissions for the "SYS" and "pg_catalog" models. These models are now accessible to any logged in user with out any authorization checks. However this JIRA introduced a new system models called "SYSADMIN", which requires data role permissions to be accessed by the user.

What I am proposing here is, modify the current functionality in the Designer Data Roles editor such that

1) Modify the check box that says "Allow read-only access to the System tables for this data role" to say "Allow this role to access SYSADMIN model"

2) Remove the automatic generation of the permission code for "SYS" and "pg_catalog" and add the following to the XML file

<permission>
<resource-name>sysadmin</resource-name>
<allow-read>true</allow-read>
</permission>