ClangSupport: Use simpler structures in some cases

The patch is mostly mechanical, but contains also a few spurious changes
from values references for some local variables, foreach -> ranged for
etc that I coulnd't resist.

Change-Id: I58f0bd972546895eb318607cbfbd7ac35caf3f23
Reviewed-by: Ivan Donchevskii <ivan.donchevskii@qt.io>

tests/unit/unittest/clangcompletecodejob-test.cpp

@@ -79,7 +79,7 @@ TEST_F(CompleteCodeJob, ForwardTicketNumber)
     job.setContext(jobContextWithMockClient);
     job.prepareAsyncRun();
     EXPECT_CALL(mockIpcClient,
-                codeCompleted(Property(&CodeCompletedMessage::ticketNumber,
+                codeCompleted(Field(&CodeCompletedMessage::ticketNumber,
                               Eq(jobRequest.ticketNumber))))
                     .Times(1);