namespace_browser: Remove most references to the modules/core package.
namespace_browser: Remove most references to the modules/core package.

It is troublesome to define modules far from where profiles are imported.
It is better if tests define their own modules, even if it introduces a
small amount of code duplication.

Change-Id: Icf995863013f03be49d13c798851e8adc1e50817
MultiPart: 1/3

vanadium/browser,vanadium/browser,vanadium/browser,vanadium/browser