CppEditor: Improve insert position for AddIncludeForUndefinedIdentifier

Includes of moc files are not considered while determining the new
include's position. Further the new include is inserted at its
"alphabeticaly sorted" position.

Task-number: QTCREATORBUG-8871
Change-Id: I67b40a6f538112753298b960da488e24f4643808
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@digia.com>
CppEditor: Quick fix "Insert (Pure) Virtual Methods"

This quick fix inserts (pure) virtual functions of base classes to the
current class. For selecting the functions which should be inserted and
for choosing the insertion mode (only declarations or with definitions
inside, outside or in the implementation file) a dialog is shown.

Task-number: QTCREATORBUG-2210
Task-number: QTCREATORBUG-2692
Task-number: QTCREATORBUG-3908
Task-number: QTCREATORBUG-5868
Task-number: QTCREATORBUG-7982
Change-Id: I8e94905afcae4778986f4c3925a494e0c6b3b8ee
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@digia.com>