Move license scanning out of the SB smoke tests

Currently, the source build smoke tests include the test for license scanning. There are several reasons why this should be moved out of there and defined as a standalone process:

* The license scan doesn't rely on the source build output. It only requires the source files. My assertion is that the source build smoke tests should be all about testing the output of source build.
* The license scan is applicable to the VMR in general and not specific to source build.

This would follow a similar pattern that already exists with the binary file validation that exists for the VMR.