CodingStyleTest: run testXHTML for each business template

This will allow to find problems when only business templates and their
dependencies are installed. When we run testXHTML with all business
template installed we don't see problems that may happen only when some
business templates are not installed.
Status Job ID Name Coverage
  External
passed ERP5.CodingStyleTest-TestRunner1

failed ERP5.PerformanceTest-TestRunner1

00:34:40

failed ERP5.UnitTest-TestRunner1

01:58:13

running ERP5.CodingStyleTest-TestRunner1

38488:22:56