Validate static uses of interfaces

Fixes #1120

Checks that all static uses of the Input and Output variables are listed
as interfaces in each corresponding entry point declaration.
 * Changed validation state to track interface lists
 * updated many tests
* Modified validation state to store entry point names
 * Combined with interface list and called EntryPointDescription
 * Updated uses
* Changed interface validation error messages to output entry point name
in addtion to ID