Autotest: Keep track of generating framework in TestTreeItem

... and TestConfiguration. This allows dropping code that
reconstruct framework ids and framework lookup by id.

Change-Id: I0bb1e6e135376e21f96b9fab7971aa097787e483
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/autotest/testconfiguration.cpp

@@ -49,6 +49,11 @@ using namespace Utils;
 
 namespace Autotest {
 
+TestConfiguration::TestConfiguration(ITestFramework *framework)
+    : m_framework(framework)
+{
+}
+
 TestConfiguration::~TestConfiguration()
 {
     m_testCases.clear();
@@ -351,4 +356,9 @@ bool TestConfiguration::hasExecutable() const
     return !m_runnable.executable.isEmpty();
 }
 
+ITestFramework *TestConfiguration::framework() const
+{
+    return m_framework;
+}
+
 } // namespace Autotest