Introduce compilation database project support.
Pass the arguments list for each file directly to
ClangCodeModel via extraCodeModelFlags therefore
introduce a dependency from the ClangCodeModel plugin.
Change-Id: Iea5760d379de1ea246382dce56de0adf7ab5673d
Task-number: QTCREATORBUG-21115
Reviewed-by: Marco Bubke <marco.bubke@qt.io>
